My experience with password managers is that it works that well on about 10% of websites/apps, and I have to resort to copy and paste from the password manager everywhere else. It's not that great
10% is pretty low though. In my case Safari does it right in maybe 80% of cases. However the ones (websites and apps) that do it wrong can be very annoying.
That seems incredibly low. Using Firefox's built-in password manager I definitely get >90% of sites. The only site that I use frequently where it doesn't work is my bank because the "card number" isn't recognized as the username.
But even copy-paste isn't too difficult. Roughly as much clicking as the magic-link solution in my experience.