My three biggest problems with YouTube are:
It sucks on desktops/laptops with bigger UI scaling enabled, some stuff just doesn’t fit.
The search function on YouTube is useless and completely broken. Instead of searching normally it:
Repeats same results multiple times;
Display unrelated Shorts nobody asked for;
Instead of displaying relevant results it shows stuff you have already watched or picked by YouTube algorithm.
You can’t skip sponsored segments with YouTube Premium. You need SponsorBlock browser extension for that.
I am Polish, so it’s not that hard for me :) But I’ve made a huge mistake of not learning where to put an accent (ударение) on each word, so my pronunciation might be way off for some words. Also I try way too hard to make sentences that make sense in Polish, but in Russian they might sound weird. Lack of practice, I guess. But I definitely see progress over time when I talk to native speakers (Ukrainian refugees mostly).