Yeah, unfortunately I have basically the same problem. The only places I can find good games are typically in the indie scene - there's lots of shooters like Ultrakill or Cruelty Squad (or Psycho Patrol R, for that developer's more recent game) but I've also found that Vampire Survivors, Different Strokes, and Cataclysm: Dark Days Ahead are all really fun, and there's lots of other games to find on Steam. Even if you don't have much money, there'll be an occasional gem in that you can find on a steep discount or, from time-to-time, for free, though that's exceptionally rare.
On that topic, C:DDA is free if you look up the name in any search engine and download it through their website, and though the graphics can be a pain in the ass to decypher, it's at least something my laptop can run and not make it sound like it's a helicopter preparing to take off. Also Dwarf Fortress is good, though that can be very taxing depending on the world size/history. (Again, that's one you have to find off-platform - the Steam version is not free for a variety of reasons.)
I'd recommend Good Old Games (or GOG dot com) as a platform that supports and helps to preserve older games like with what you're talking about. I've recently bought a pack consisting of the OG Doom and Doom 2 on there, and I'm currently also playing the original Fallout, though I got that one on Steam a while back. (The original Fallout may or may not be bugged on GOG - I haven't bought it myself to confirm, just out of precaution.)