I think that might be a mobile limitation. Profiles address that problem but I'm not sure if Android or iOS give developers the ability to autofill profiles.
Bitwarden's UX is pretty poor but the way I see it is that's what $12 a year gets me. :)
Hmm, I've tried LastPass, Enpass, a handful of Keepass clients I can't remember the name of and (shortly) 1Password, and I can't really find anything Bitwarden does that much worse than any of these. To be perfectly honest, they're all kind of clunky, IMHO.
I feel like I can think of a lot but I'll give you one that, to me, is Bitwarden in a nutshell:
What happens if you open your browser, go to https://news.ycombinator.com/login, and hit Bitwarden's autofill shortcut? Nothing, because you didn't log in to Bitwarden first. Pretty much every other password manager will ask you to log in and then they'll autofill.
Natively integrated password managers like Firefox or Chrome are in a much better position to push for UX but you can see they aren’t that much better either.