Star Trek Social Club

Holograms aren't stable in the long term. They will start to come apart after some time. That, and they constantly require power to maintain. A bed and furniture does not, and will still work if the ship needs to go without power for one reason or another. Most things someone might put by hologram can be done by replicating the thing, instead of using a hologram. Most rooms have a replicator, and excepting furniture, which you might need to ask engineering to make for you, you can just make it yourself.

Starships aren't lacking space by any means, so there's no need to stick people into a broom closet.

Though there are things like that. The Ba'ul "migration" ship was basically that, where the entire ship was meant to be a holodeck. In the 32nd century, rooms are basically holograms, except that holography has been superseded by programmable matter.

Power?

Considering how often a single holodeck tries to take over the ship/kill its occupants/malfunctions, the fewer the better.

I remember a line in at least one episode that claimed holodecks consume so much power, they run on their own independent power system and aren't connected to the warp core.

Can't remember which episode it was, but it was likely one of the two parters where the Hirogen take over Voyager and have the WW2 sim.

OG Discovery had some kind of combat simulator (kind of a proto-holodeck) that Lorca and Tyler used to train for a mission.

After the 31st century refit, the cabins used programmable matter for their furniture, etc. My understanding is that programmable matter is the transistor to the holodeck's vacuum tube (i.e. it made holograms obsolete). Ok, I said that, but there are advanced holograms at HQ, so I guess holography hasn't gone totally out of style. I don't recall if it was ever established as such, but my head canon is that programmable matter is more efficient for "static" objects since it doesn't need energy to maintain form, just when it changes (unlike holograms which require constant energy). That would explain why PM is used for furnishings/decor and holograms are still used for humanoid constructs.

As for why all rooms aren't holodecks/suites in the 24th century, probably due to power consumption. In VOY 4x18 "The Killing Game", the Hirogen had Harry Kim expanding the holo emitters throughout the ship which seemed to be putting considerable strain on the ship's power system (despite not being in battle or at high warp; perhaps not in warp at all -- been a minute since I saw that episode).

While the Prometheus had ship-wide holo emitters and seemed fine power-wise, there's a difference between projecting an EMH (or two) versus simulating an entire environment plus the associated NPCs.

Probably because it'd be too expensive and I'm not talking about money

Not everyone wants to sleep in a death trap.

Warships need to be able to keep functioning even if they take damage, loss of power, etc. A holographic system seems to be fragile, and requires lots of other ship systems to be fully functional.

Not to mention energy use, purpose-built compartments probably use less energy just to exist

I imagine they prefer to be grounded in reality, as over-use of the holodeck is shameful.

1. Energy. In TNG, the holodecks burn a lot of energy. Can't imagine what would happen if you turned every room into one.
2. The holodeck isn't a Tardis. The space inside the holodeck is an illusion created by the room. The room can make the space look infinite, and the floor can function as a hard-light treadmill that let's you explore that infinite space, but the room still needs to be large enough to accommodate all the real-world things in it. That's why they're so large in TNG and Voyager. Holo-quarters would still need to be roughly the size of regular quarters.
3. Same problem with the bar. Sure, you could make anyone's quarters look like Ten Forward, but if your quarters fit 3 people, that's how many people can drink there.
4. The sickbay would still be essential because the problem isn't medical equipment, it's staff. Unless you're going to have the medical staff running all over the ship making house calls, having that staff in a centralized location and having the crew come to them just makes more sense, especially in an emergency. Emergencies are also why that equipment should never be holographic. If the ship is under attack, the last thing you want is sickbay disappearing because of a phaser hit or having to turn off the medical equipment to power the sheilds.

I'd say the biggest reason is energy, like everyone else. But also, being able to make your room into any fantasy scenario you want would probably lead to problems with adjusting to everyday life. They don't need a whole ship full of Barclays screwing up at their job.

As people said, the Holodeck uses a lot of energy, "Homeward" is an episode who show this.

I thought the same. It helps to watch the first episode of the next generation. Will talks to wesely about it and its a rare thing at that time and sounds like it takes a lot of resources. Later episodes the holodeck using a lot of power comes up. People have to sign up for them and I took it there is no point in making more holodeck rooms than is prudent for the amount of power they draw just for leisure (mostly) activities. All the rooms have replicators but if someone was running it constantly it would become quite the power drain and we see in voyager that with no source of resupply have to ration replicators (although curiously I don't recall them rationing the holodecks, but maybe they did). As far as discovery in the future you see the energy issues and they use that programmable matter which I think is supposed to be more energy efficient.

High energy use. Anytime the power goes out or gets diverted to other systems, you’d lose your bed, etc.

It’s also possible that the holodeck re-creations of things aren’t as realistic feeling as they look. It’s an illusion after all. So maybe a lot of it is just designed to fool the mind, not be comfortable/realistic.

They didn't go into depth at all, don't believe we even have one with a name, but they talked about seeing federation ships made entirely of 'holographic containment walls' in Discovery Season 3. Pretty sure it was when they first arrived at federation headquarters in the future.

There was also that ship in insurrection where it was just one giant holodeck, but still existing inside a regular ship. The concept just hasn't made it into something that's broadly popular in the mainstream trek fandom.

wait, does Discovery has a holodeck?

They actually seem to have what you're describing, more or less - Burnham was able to run complete holosimulations in her quarters.

Prodigy has holoemitters on every deck and is able to reconfigure the bridge using them. It is possible but they just need a reason.

This is a fun thought experiment and I'm kind of surprised Discovery didn't do something like this with holodeck tech in the "future" since the writers weren't afraid to do other tech-taken-to-natural-conclusion like tiny phaser transporters (or whatever those were).

Semi-related but I always thought it would be cool to see a Star Trek future where things have advanced so far that it would appear to someone like Picard like he and the Enterprise appeared to the Mintakans.

When holodecks were introduced in TNG, they were presented as brand-new bleeding-edge technology that the characters had never even heard of before. This was reinforced by the fact that they almost immediately got a major update from the Bynars and also had a bunch of weird bugs and glitches to deal with.

Voyager, which was only a few years newer, had an obviously more advanced holographic system, with emitters in sickbay and whatnot.

IIRC, other, even newer, ships had holoemitters all over the ship. Clearly, the technology was rapidly advancing and proliferating in the TNG era.

As for Discovery nonsense, ¯\_⁠(⁠ツ⁠)⁠_⁠/⁠¯

In emergency cases most holograms can be shut off to match increased energy demands by weapons and shields.

Disengage the safety protocols and suddenly you've got weapons and shield emitters than ought to work just as well as their material counterparts, but can't be damaged (or any damage can be instantly reset). We know that holograms can be projected into space so the only limitation would be the range of the holoemitters.

Maybe they are and nobody has realised 🤯

A) waste of energy

B) horrible source of possible complications, problems and Desasters.

Guess that's already enough reasons. Good idea though.