HN userbase is not representative of the large majority of the users of a service.

Most of are fully capable of using a password manager, some even self-hosted that we expose via Tailscale, but for a lot of users, they are using a service to get things done and authentication is a necessary hurdle.

Sign in with Google/Apple/Github solves that.

Counterpoint: my parents managed to lock each other out of their shared Amazon account after being coerced into "upgrading" their login method. Thankfully they managed to reset it somehow and go back to saved passwords, which Just Work™.