The thing that convinced me in the end was that Kite had a super heavy editor integration UX that needing a constantly-running Electron "copilot" app, even uploading some of my code without clearly asking for consent first. This has maybe changed now, but at the time that was my impression.
Meanwhile, TabNine has almost no UI, it's just the tab button and nothing else, and somehow the autocomplete "just worked" amazingly well with any language I wrote, including English prose. The ratio of "fuss" to "gain" was just so different between the two. One I barely remembered I had even installed anything, my editor just suddenly became a pair programmer overnight, and the other felt like I was running a whole electron app just to get occasional library headers autocompleted and docstrings on hover (in only a few supported languages).
I wish the Kite team all the best though, and I hope to see their solution grow and improve. There is definitely room for more players in this space, and I know they've learned many lessons from their past issues with code uploading UX, so I hope people give them a break over that past PR gaffe.