Yeah. I'm perfectly fine with e.g. Twilio being able to tell Verizon "oh, we have authorization to send from $x", Verizon going "uh huh, go ahead" because they

Yeah. I'm perfectly fine with e.g. Twilio being able to tell Verizon "oh, we have authorization to send from $x", Verizon going "uh huh, go ahead" because they trust Twilio not to mess around. But then, if there does turn out to be an issue, Verizon is on the hook, and they'll turn around and charge that to Twilio. So, they'll be fine with letting large companies like Twilio spoof on their network, but they're not going to let RandomCo spoof. So forcing the fine on the last step in the chain forces everyone to carefully consider who they trust, which is as it should be. Nothing wrong with trust between trusted parties, but clearly the current system has untrustworthy parties given too much power.