It’s great on iOS! It integrates into the password manager just like LastPass did, so you get the “Passwords” button or the account name. If you have faceID or touchID set up, it’ll auto auth you and autofill the password. Bitwarden is seriously almost a drop in replacement. The biggest difference is the extension settings in browsers don’t autofill by default in the same way as LastPass. Also you can self host bitwarden (what I do).
Any shortcuts used by extensions based on the WebExtensions API are changeable. If you're on Firefox, press Ctrl+Shift+A (or go to about:addons), open the gear menu, and click "Manage Extension Shortcuts".