I don't think it was Jack's fault, but Twitter went from something that (granted they did tend to do a few shady things from a UX perspective) was fine and largely worked but did have a massive censorship problem, to something that works less well (seriously? i can't see posts chronologically without an account? on TWITTER???) and apparently still has censorship (although I was mostly preoccupied with covid, actual doctors getting banned for truthful information, pre-Musk)