By the time mobile could run Flash, it was too late. Between Apple & Adobe, it had no shot of making the transition. But before that, Flash was pretty amazing.
For all the many reasons people might dislike Apple, they were 100% in the right on this topic. Flash needed to die. It got everyone to collectively push the web standard technologies ahead into something way, way better.
Sorry, that's simply not true. The tech was ahead of its time. The implementation was intuitive. Only developers and Steve Jobs hated it, because Flash made it way too easy for anyone to make something fun.
Sometimes good products happen despite bad technical foundations.
Let me introduce you to itch.io[0] where, in fact, people bang out HTML5 games at a rate that will stagger your eyeballs.
(Even me, a resolute "backend-only" dinosaur managed to use a HTML5 game engine to knock something out playable in an hour or two.)
[0] https://itch.io/games/platform-web - ~689k results