In 2007 flash could run 3d games, do shaders, have multiplayer, run physics manipulation, have 3d sound, do bitmap manipulation, socket programming, and had documentation built into the editor.

Even now html/J's can't do all of the things and most of the things that you can do, are not as fast. While browsers are stuck with legacies to uphold. Flash had no dom to worry about, untyped language (as3) or had css holding it back.

General argument was flash sucks because people make terrible content with it. Which is like saying I hate having hands because I trip things over.. so no limbs = no mess PERFECT.

In turn I think it helped push native apps. Since plain Js/html app just sucked in comparison when it comes to experience and capabilities.

Flash should have been open sourced. Hopefully with webgl and web assembly someone can step in and create something similar