1: VR motion sickness is an issue some people get, unfortunately. It happens if you have a mind that refuses to acknowledge and accept conflicting information from your inner ears and your eyes.... which people with motion sickness often have. When you try to "push" yourself to accept VR movement when you are already feeling sick from it, it gets worse. You're supposed to only do a few minutes of movement in VR at a time, and stop when you start feeling sick. Getting over this is referred to as "getting your VR legs". Once you do, you will be able to do hours without it showing up, and motion sickness irl might get less problematic.

2: Standalone VR, which runs a special version of Android, as much as I'm not a fan, is already here and usable with the (absurdly affordable) Meta Quest series, the (Chinese alternative) Pico, the (Apple tax'ed expensive) Apple Vision, and possibly Valve's new Index.

3: Not every game is meant to be played in VR, but vehicle games and a lot of other unique experiences that require you to have your head on a swivel or interact with lots of in-world objects in a 3D space? Amazing. Playing Flight Simulator without a VR headset just isn't the same.

VR is great when playing Warthunder in aircraft, where you can easily track an opponents plane while maneuvering your aircraft after them.

For tank and naval battles - meh.

All of the things you listed are either being worked on, or are mischaracterizations of the state of VR.