> but IRL the response I've seen from most users when it doesn't match is to assume the integration broke and manually copy/paste it in.
I've seen people do this AFK as well, and I'm always helpfully suggesting them the correct way of solving this: verifying the URL again, and if correct, add it to the password manager so it remembers in the future, and never copy-paste passwords on the web. Basically 50/50 if they take the advice or come back after a week asking if it's safe to copy-paste the password into the website, and I try to inform again.
Shockingly, I saw one developer peer copy-pasting a password into a website, but I guess for these people there is no hope.
There are too many websites where this is broken for me (even with Firefox's built-in password fill) to go as far as to never copy-paste passwords. If web devs actually implemented it consistently, I might be that draconian about it, but asking them to do that when we already have the '200 MB of JS is needed to view this page' problem, I have my doubts we're going to see this problem going away any time soon.
Probably the whole authentication thing shouldn't be implemented by the website at all. There should be some standardized way to ask for authentication that's implemented by the browser or the operating system.
It should be a big red flag for sure, but the reality is most users aren't going to understand that. They got told to use a password manager by someone or find it convenient, but they don't understand the security flow enough to catch that it's a potential attack, or how to resolve it safely.
Historically I've seen lots of sites do a subdomain shuffle for login pages every now and then which routinely breaks domain matching, introducing false positives that users have to deal with, making them numb to the threat too. Passkeys baking in the domain check with no workaround means that sites can't do that, which is a benefit.
My password manager's browser integration breaks on every update of Firefox, which seems like it is a weekly affair. I got rid of the extension, and copy/paste everything.
Password managers were never meant to solve the problem of phishing, and aren't really capable of that. They solved the problem of password reuse. They do that just fine.
Your last sentence got me good, as I'm a developer who copy-pastes passwords into websites (from a 12? year old KeePass database, for whatever that's worth).
I've tried using the Firefox integration in the past - more than once - and I don't know... it had so many warts that I got fed up with it and turned it off. And now I have 1Password (from work) also doing its best to feed me credentials all the time. So trying the KeePass integration again is going to have them both drawing suggestion dropdowns all the time..
But ok, I'll give it another honest shot. Because of your comment.