This take doesn’t make sense unless you’re comparing Flash to current technology, rather than the tech of its time. It’s like saying CD players were awful: sure they’re awful NOW, but they had a time and a place when they were the coolest thing around.
Similarly, the only reason Flash had “bad performance” on low end devices is because people were using it to do stuff that web tech could not do. It took over a decade for web tech to catch up, and 20 years later we still don’t have tooling that’s as good as Flash was (other than Adobe Animate itself).
Calling it “terrible for video” is completely backwards! Flash became the standard for video on the web for years because everything else was terrible and Flash was the only thing that worked. There’s a reason that YouTube used Flash to play videos for the first ten years.
