-- (Please lets not do the fanboy "Flash is garbage" here - even if you do feel that it was heating up your CPU with ads - it would have taken a lot less than 8 years to fix that then to reinvent everything and find out that money still makes the world go round.) --
To say that Flash on mobile was great but Apple killed it anyway, gives Apple way too much credit. Flash on mobile killed itself.
They had more than 8 years to fix it on the desktop and didn't. They had more than 8 years to make the Mac version perform at rough parity with the Windows version and didn't.
Either way... "it's fine, we'll make it work well within a decade" is NOT a good message to your users.
Just discussing monopolies and drawing parallels.
To be fair Adobe was always pushing Flash as a cross-platform, cross-browser system - mobile browsers kind of changed the game and required a different approach since they were so tightly coupled to the OS and controlled by its vendor (BTW there was also a time where Microsoft was accused of monopoly for bundling its browser with the OS - doesn't seem to apply to iOS though).
If it was supposed work cross-platform on 2 mobile platforms - and one platform says no, well then 1 platform is not cross-platform any more is it? Adobe then gave up and stopped developing it - but yeah, Apple effectively did kill it. Especially since it was still a very early try. I mean up until 1-2 years ago even normal css/webanimation was laggy on mobile browsers.
Even though my Mac never had significant problems with Flash. I mean - fix what? I don't have Flash installed any more but my fans still spin-up with multiple tabs and overactive pages trying to open a bunch of animated or video tabs.