[floss_silicate]

I tried to set up a Twilio number specifically to handle these services that demand SMS for login.

Weirdly it only works for a minority of services, I expect many use Twilio to send their auth texts and Twilio blocks sending these to their own numbers?

[dimmke]

The reason most services require a phone number is so you can't just create a new account if you get banned and ideally your account is somewhat tied to a real person. They ban VOIP numbers because it would defeat the whole point.

[TwoBit]

What's preventing someone from getting mutiple regular phones and accounts for them then?

[closeparen]

Cost. You can do it, but not hundreds of times like with an email address. Probably not even 10 times before you give up and do something else.

[closeparen]

Part of SMS verification is to raise the cost of Sybil attacks. Well known sources of cheap bulk phone numbers are often banned for that reason.

[sushid]

I'm not sure if Twilio blocks sending to their own numbers but you can't receive from or send to short codes, which will limit you a lot when verifying with services like Uber.