People romanticize Flash these days. Especially people who weren't old enough to struggle with it.
Used improperly – as it very often was – Flash was a resource hog far beyond even the craziest of today's web sites. In many circumstances it could actually crash your computer. Not just the browser, but the entire machine. Sure, the operating system and the browser were complicit, but I'm not going to blame a broken window for not being bulletproof. Plus, it seemed like there was forever update after update after update every time you tried to view a fancy web site. Updating plugins isn't a big deal today. It was a big deal when it happened over a 56k dialup connection.
Can you imagine someone today thinking, "Oh, this looks like an interesting web site. I'd better close every other window and program on my computer, so it doesn't crash." It's unthinkable.
I hate that today's web sites are all boring and desaturated and flat. But I love that I can browse the web and keep a dozen other programs open and doing work at the same time.
Watching all of the new things people are doing with canvas and WebGPU and whatnot makes me think we're heading back to the bad old days of Flash. It seems like an arms race between people who want to turn a browser into an operating system, and browser makers trying to keep everything tidy.