Worth noting that the SWF format was towards the end of its lifecycle and open standard as well. Fully documented with open source players and tooling available.
As someone who has used Linux on the Desktop for 20+ years, I can say with pretty high confidence that open source flash players could not run more than a trivial amount of real world flash content at the end of its life cycle ~10 years ago.
Ruffle.rs looks pretty promising for playing flash.
Adobe still has the editor as Adobe Animate - if they made it more widely available, I think there is a big demographic of designers that would like to make a bit of animation or active graphics that is not being served any more.