There are huge archives of flash animations and you can install a safe “emulator” for playing flash that even runs in your browser. Look up Ruffle. I can’t remember the name of the big archive site I used, but it didn’t take much googling. I know I was able to find Homestar, Larry Carlson, Adam Phillips (bitey), joe cartoon and salad fingers as well as a ton of games from back in the day.
I buy multiplayer games on steam since that’s where my friends are. I pirate almost everything else unless I want to support the developer (typically small indie games or high quality stuff like FromSoft). If I buy a game, I do prefer GOG but steam can be convenient, especially on Linux.