[chmod775]

Just today a delivery service wanted to send an SMS to validate my phone number, so I was forced to use a mobile phone number rather than landline. Landline often makes more sense, because usually they'd call to reach someone in the household the item is being delivered to, not a specific person. Other delivery services require a landline number, which sucks for people who don't have one.

Some services limit you to one account per phone number. Not only are there 5 numbers that route to my card (probably common given that this was a local provider's standard offering some time ago), once I even got a one-time token for some account a previous owner of a number was apparently trying to reset. It helpfully informed me which service it was for, so I could have likely used the fact that I now control that number to take over their account.

Using phone numbers for 2FA/account resets is worse than e-mail, even ignoring the fact how vulnerable telephone networks are to spoofing/intercepts.