Ruffle for the win! It's an open source flash player emulator written in Rust. There is a browser extension that you can use to player flash games just like before! The ActionScript compatibility is very impressive! If you want to contribute to the project, here is more information. If you want to experience flash games in a convenient way, you can go to this site : https://bluemaxima.org/flashpoint/ to get access to a huge archive of flash content.
You can import my website's list of games for flashpoint here