also thousands of games made with pico8 on the net live. Sure pico-8 is not a replacement for flash but people are posting live games and they are making them quickly. Celeste, one of the top 10 games last year on many lists, started as a pico8 prototype live on the web.

Also flash never worked cross platform in the modern sense (phones + tablets + desktop). It's a very hard problem and no system I know of handles it automatically for anything more than simple HTML text forms