I made Flash Games back in the day. Here's my old profile on Newgrounds: https://cableshaft.newgrounds.com/ One thing Flash had that nothing else has really seemed to replicate as well since, is an environment that both coders and artists could use. I'd collaborate with an artist, they'd make their animations within an FLA, send it to me, and then I'd copy+paste into the project file, and it'd just work. I could even…
Maybe Rive fits this well enough? (Not affiliated, just looked into it at a time from a render engine perspective)