Aren't password managers, especially cloud-based ones like LastPass, also the same thing: they hide all your passwords behind a single master password (and a MF

Aren't password managers, especially cloud-based ones like LastPass, also the same thing: they hide all your passwords behind a single master password (and a MFA optionally). Granted, their only job is to secure your passwords, but it's effectively equivalent to a single SSO service from a protection standpoint (if all your accounts would accept that SSO login).