I thought the same. But it is necessary for the vast majority of games. It is not just an emulator for the .swf (and other formats) content you need, you often need bespoke proxy servers and server emulators to bypass some of the old DRM.

There's ruffle: https://ruffle.rs/

iirc support is generally good, but some versions of flash/actionscript have issues (at least last time I checked).