No, I think he's mostly right but it is a little more complicated. Most services demand a cell number verification on account creation for user tracking and identification under the guise of security for you. The SMS 2FA setup flow just helps push the user into coughing it up and helps sell the security cover story. Theoretically this helps prevent abuse, but there's no reason they have to abuse the data themselves after getting it for that. Its just that they will. They'll even lie to your face that they only use the number for security purposes and then use it for advertising anyway.

https://www.eff.org/deeplinks/2019/10/twitter-uninentionally...

https://techcrunch.com/2018/09/27/yes-facebook-is-using-your...