Adobe refused to make the flash player work reliable on OSX back in the day. It was Adobe's fault, and anyone that used the web on a Mac in the 2000's can confirm that.
Flash could have survived if Adobe open-sourced the codebase. But they kept it in-house and didn't have enough resources to mutate it in light of rapidly-evolving demands placed on web technologies by mobile architectures. I suspect there'd have been plenty of volunteers stepping up (including, possibly, from Apple itself) if Adobe hadn't decided to dragon-hoard its IP.
But in the web era, IP isn't king; communications is.
iPhone apps were fast and responsive on low end hardware precisely because apps were natively compiled and didn’t run in a VM. Did you ever try running Flash on early high end Android phones?
I 'm sure they were slow. but i m talking about the authoring tool and scripting language. I presume apple could optimize that to be fast natively. Judging from how HTML UI frameworks evolved over time, it's as if we ended up reinventing Actionscript
So what was Apple going to do during the first 4 or 5 years? Every single mobile platform that tried using HTML frameworks for their apps failed and were slow.
Blackberry, Palm, and Microsoft all tried it. Android itself was slow as molasses for years because of its dependence on a VM instead of a completely native stack.