One Less Password
Not a bad idea but the chief drawbacks I see:1. Needs a very long-lived session to be convenient. Elsewhere they note their's is a whole year.[1] That's a long time to go without reauthenticating a client!2. Authentication is or should be a much more common event than recovering a lost password, and now that's totally dependent on your email provider. One concern is latency.. a minute can feel like an hour while waiting to log in to your account to do something urgent. But also worrisome is provider downtime, spam filters, etc. all can block you from accessing your accounts.Of course the way they "deal" with #2 is by just trying to avoid authenticating you very often (#1), which is not a generally-applicably awesome security practice. Might be ok in some cases but I wouldn't classify that as an overall "better" way to sign in.I think a better way to solve this is at the browser/OS level with built-in password generation and management. And that's actually a third drawback to this approach.. it's incompatible with password managers.[1] https://chrisdecairos.ca/one-time-passwords-pt-2/