Going from my experience with 1Password here. There are a few ideas, first is as you mentioned, it’s 1 password to remember, the rest can be randomly generated

Going from my experience with 1Password here. There are a few ideas, first is as you mentioned, it’s 1 password to remember, the rest can be randomly generated and you don’t need to know them. In the case of 1Password, data is stored at rest, if the vaults locked it can’t be read, well, not easily. Auto fill helps detect phishing attempts, if the domain is different 1Password won’t auto fill It also can detect breaches and store TOTP if that tickles your fancy. Auto fill is the key point of a good password manager, it makes entering logins trivial, I use biometrics to unlock on all my devices, then it fills in my details for me and away I go.