I've only had like 1 issue on desktop in the last like 5 years. Mobile I've bumped into a few hiccups with forms, sliders, and other elements not working properly. If I can't resolve the issue by requesting the desktop site I go to my computer or Chrome in an absolute emergency.

That said, I'd take a (waaay) sub-1% failure rate any day in exchange for having the joy of uBlock Origin on my phone. If you're on Android, I can't recommend Firefox enough thanks to the add-on support.