Yes, it's true that SMS-based authentication has its flaws, but it's far from useless/harmful in many contexts. The same strawman arguments used here would also find TOTP "wholly ineffective" which is an absurd conclusion.

A main goal of security engineering is to increase the difficulty level for attackers. SMS authentication has demonstrated its ability to do this in a highly accessible, albeit imperfect, manner. I feel that the author severely underestimates the practical difficulties of widely deploying "Unique Passwords and U2F".

I strongly disagree with the conclusion that "SMS-2FA is not only worthless, but harmful" and highly recommend consulting a security professional before entertaining any of the arguments or following any of the suggestions in this article. I don't like leaving negative comments, but this is at best borderline misinformation that has the potential to create severe consequences.

Some more context, if you want to consider a more balanced perspective: https://doublepulsar.com/infosecs-fantastic-fear-of-everythi...