A $600 PC with a dedicated graphics card is probably going to have a worse CPU than an M2 or M3 Mini, and probably no Thunderbolt. You would only be cross-shopping a PC like that with a Mac Mini if you were thinking of graphically-demanding productivity work, like video editing or Blender. If it's for gaming then the Mac wouldn't be in the running at all.
Ghost managed hosting gets more expensive as you get more subscribers, I don't think Patreon does. You also have to set up the payments processor yourself (usually Stripe), and if you self-host, you need to set up an email service like Mailchimp. Ghost also has much more basic community features than Patreon, and doesn't do per-user RSS feeds, so stuff like subscriber-only podcasts are more difficult.
The M2 Mac Mini is $599, or $499 if you can get the education discount. There is not a (new) Windows PC in that price range that has the same performance (especially performance-per-watt) and Thunderbolt 4. The M1 MacBook Air is getting a bit old, but it's on sale for $600-700 pretty often and will knock the socks off most PCs in that price range, especially in build quality.
Apple's pricing gets ridiculous when you try spec'ing up with certain memory or storage upgrades, sure, and most internal upgrades are a no-go. The base models of most of their computers are incredibly competitive, though.
Good news, there is a subscription service to prevent that and also still pays the creators.
The email signup and user management panel needs JavaScript, yeah.
I don't like ads either, but they are the only functioning way of paying creators outside of direct payments, especially with economic inflation and competition from streaming services eating away at people's budget for media. No one else has a solution that works under capitalism.
The two options for compensating a creator for their work online are advertisements or direct payments. There are no other functional alternatives. In a better world, more countries would have grants or universal basic income, but that's not the world that exists right now.
Because it’s an additional source of revenue, and they can provide rewards outside of YouTube.
If you don’t like Google keeping a cut, then sign up for all the Patreons for everyone you watch.
Even if official support isn't possible past a certain point (Google and Samsung are pushing 7+ years, fwiw), all phones need to have a bootloader unlock mechanism for unofficial support past that point. LineageOS or mobile Linux with some broken functionality is still better than nothing.