Search is atrocious.
UX is awful. It's 2023 and whatever version I'm using, it still doesn't accept markdown properly. And it's wysiwyg mode is broken most of the time too - try selecting text and setting it as code/preformatted and the entire comment, or description changes instead.
It's a jack of all trades, master of none.
It's funny, because I was one of the first adopters of it for Megabank, back in the early 00s, because it was fast (flat ui on top of our own Sybase instance), and its UI was simple.