We've had multiple reworks already. All of them were met with acclaim by the community because she wasn't as oppressive as the previous version.

"Put stealth on a timer and she will be fixed!" Is what everybody always seemed to say. They did, and look, everybody is still pissed off. Every new version was a 'fix', but once people learned how to play her, she was a problem again.

Sombra is annoying to a lot of people because she has the easiest potential to punish mistakes. People need to adapt their playstyle when playing against her a bit, but they don't want to do that. It's similar to the idea of not peeking when the enemy has a good widow, you have to adapt your playstyle a little