Anecdotally, I noticed a browsing speed up when I switched from LastPass to Bitwarden on older laptops.

I recently switched to Enpass after LastPass started having major issues in both Firefox and Chrome. I was having to remove and reinstall it at least once per week.

Enpass has been great. The setup with Dropbox sync isn’t as quick but that’s just one per device. It’s very speedy and hasn’t gotten in the way at all.

Isn't that weird - not a programmer but ... surely the only code they need to run on every page load is to add an event handler for forms to check if a login form has been focused? (At which point their add-on runs). What else are they doing?

Browser extensions are usually the attack vector for password managers.

I use the native desktop apps for them, previously LastPass and currently Bitwarden. The UX suffers a bit but you at least you gain some security.