Netflix's shiny new compression scheme a couple years ago didn't work on my Sony TV's buggy silicon. The only way I got that fixed was by knowing someone on the inside.
Hulu usually can't make it through an episode without the video freezing at least once. Sometimes it just refuses to work at all until I completely reboot the TV.
HBO Max's UI is just really cheesy and slow, but whatever it's fine.
Paramount+ is my new favorite to hate on. The UI is maddeningly glitchy and lethargic. I pay for no ads, but it plays ads anyway, on Star Trek episodes from 1996. It doesn't remember progress in a show more than once every week or two, just enough to remind you that it's supposed to be a feature. On my phone, it doesn't hide the typical menu overlays unless I do a complex sequence of finger taps. One time I tried to file a bug report from inside the logged-into app, and I got an email back claiming that they would love to consider my concerns but can't because they don't have an account associated with my email address.