Honestly this seems a very "good", manageable business strategy. Cell phone number provides one method of 2FA that is easy (but not necessary secure) to use --

Honestly this seems a very "good", manageable business strategy. Cell phone number provides one method of 2FA that is easy (but not necessary secure) to use -- text messages, provides some level of guarantee that the account owner is not a bot, and means that the user is very likely to spend money in phone apps where PayPal is one of the allowed payment methods (e.g. Uber). Companies have little to lose by ignoring users who don't use cell phones.