Jobs deserves credit for a lot of the way things went in the computing world but I don't think "killing flash" is one of them. Apple and Flash only (publicly) crossed paths when the iPhone was released in 2007. Even then, Flash was widely disliked by users for a bunch of very good reasons:
* It was yet another thing to install. (Most non-tech-savvy users didn't know how to install a web browser, let alone a browser-specific plugin.) I was an "expert" computer user and I still had trouble getting it to work quite often.
* Flash apps were very resource-hungry on the slow machines at the time. Not quite as bad as Java, but still pretty bad. You had to wait for them to load, and when they consumed an outsize amount of CPU and memory compared to the value delivered.
* A lot of enterprise software started getting written in Flash (vSphere 6, anyone?). I feel bad for every IT department that had to put up with this. Of course, before and alongside that it was Java.
* The Flash runtime was a huge source of computer-pwning exploits. "Click to play" flash was a good idea but about a decade too late to make any difference.
No, Flash was never particularly well-liked by ANYONE except animators, web video game companies, and web ad companies. It was going to die eventually. Even if we were to accept "Jobs killed Flash" as true, that would make it one of his _least_ successful endeavors since Flash only went EOL this year, 14 years later!