The same way we have the robocall situation (thanks to shady telcos that turn a blind eye), the same way this system will be bypassed with similar telcos offering massive blocks of numbers at very cheap prices per unit (Twilio numbers seem expensive at small scale, but I guarantee you will get those prices down if you commit to getting like a thousand of those or so at once).
What you're saying is, this has increased the cost of creating a Twitter spam account from practically zero cents to... what, 50 cents an number? A few dollars per number?
That's a huge leap, and it sounds like requiring a phone number is a great way to increase the cost of spamming.
