Arguably the 2nd biggest: the biggest was when they made that shit mandatory, in that I can no longer go into Settings and uncheck "New UI". The breadcrumb placement[1] alone almost made me rage revert to 2023.something since it was so instrumental to my workflow. Maybe by next Oct I'll have retrained my brain to look in the new location, but goddamn was it that important to them?

1: yes, I am aware of the Setting that says "breadcrumb placement = top" and I am also aware it does absolutely nothing. I'm currently too burned out on their process to open a YouTrack about it