It was the player that wasn’t great.
(i'm interpreting 'flash websites' as 'websites made in flash'. i'm not referring to websites that contained flash applets.)
Most of the flash sites that I really remember consuming were actually very simple documents that relied on flash for presentation, so it would be easy to provide a screen reader friendly version of the content.
Also a lot of flash content was cartoons and games which don't lend themselves to screen readers anyway.
This however also lead to an abuse and for a while you had websites, fully in flash which broke so many things (deep linking/bookamrks, browser history, etc.) combined with unintuitive navigation and slowness due to animations ... plain overuse of an otherwise good technology.
Truly we have failed to learn from past mistakes.
I took a 3 year break from anything Frontend. Felt like I had gone through a time machine.
And the standard libraries, cross-platform support, and industry-trailing IDE. They didn't even have a stable debugger for years but that didn't stop them from charging $800/seat to see if they'd fixed any of the problems.
So your solution is to dig the hole even deeper?
He he, that's a funny link. We know the end-state of absolutely unfettered capitalism :-)
We've had it, that's why they invented the guillotine. It was called "feudalism".