Oof, my Bitwarden account was created a while ago and was set to only 5,000 iterations. You can see and change the number of iterations here: https://vault.bitwarden.com/#/settings/security/security-key... (or if you don't trust links for something like your password manager: log into your web vault, click on the top-right dropdown menu, then Account settings > Security > Keys).
I've updated it to 600,000 iterations and so far don't see any noticeable impact on performance, both on desktop (using the Firefox extension) and on mobile (iOS).
I've updated it to 600,000 iterations and so far don't see any noticeable impact on performance, both on desktop (using the Firefox extension) and on mobile (iOS).