reason Flash ever became a thing was because web designers were begging the W3C to add multimedia capability to the HTML spec. The W3C saw the web as a medium of information exchange (the way Berners-Lee originally envisioned it was a way for researchers to exchange journal articles they'd authored). They saw the requests for multimedia capability as the petty desires of advertisers and marketers. You see, photos and text you can scan and grok as quickly as you want in whatever screen format you want. Audio and video are limited to the speed and format that the creator sets. So the W3C saw adding multimedia capability to HTML as counter to the web's original design goal.
Then web designers discovered this little thing called Flash. It was an artist's tool for transmitting animation
over slow Internet connections (here's a YouTube version
if your browser doesn't support Flash anymore). Instead of retransmitting redundant information like video does, it transmits backgrounds, scalable vector graphics, and sprites just once, and lets you animate them with on the client side. That's all it was designed to do - help artists create animation. It was never designed to be a multimedia web platform
But since the W3C refused to give web designers the hammer they asked for, the designers grabbed the closest thing they could find which resembled a hammer and started to hammer away with it. Flash began to be used for multimedia - animated websites, ads, and movies. That's why it was so full of security holes. The guys who wrote Flash never imagined it would become The Global Standard for creating multimedia websites. They thought they were just making a simple way for artists to create animation that could be transmitted over 56 kbps dialup lines, and didn't give any thought to security.
By the mid-2000s (long after the tech bubble), the problems with Flash were becoming clear. The W3C still refused to budge from their anti-multimedia stance, so the web browser developers themselves got together and began coordinating a way to add multimedia capability to HTML
to help replace Flash. They came up with what eventually became HTML5 when the W3C finally relented. All this was going on years before Jobs wrote his "Thoughts on Flash" letter, but because those in the print media were widely ignorant of any of this, they mistakenly saw Jobs as the impetus behind the switchover. To repeat what I constantly seem to have to tell Apple fans, just because the first place you
ever saw something was on an Apple product, does not mean Apple invented it. (Here's pinch to zoom in 1988
Outside of the whirlwind of controversy over web security, Flash continues to live on
in its original intended design purpose, and rather successfully at that