Ask HN: Why don't all websites allow sign-ins with temp code sent to mobile

I agree with the other commenter that noted that SMS isn't secure, but passwordless login is a growing trend, I think.

https://auth0.com/docs/connections/passwordless/faq

https://www.okta.com/security-blog/2018/04/is-passwordless-a...

Granted those companies might be a bit biased (they both sell a passwordless plug-and-play solution), but considering that the password reset flow does have the same vulnerabilities I think they have a valid point, regardless of bias.

If you mean SMS, it’s not secure.