The post you replied to barely even mentioned Twilio. It made no comparison to email or IM. It never said those wouldn't have worked. You seem to imply that choosing to use Twilio at all indicates a fault in one's communication setup...because they should use email instead?

The funny thing is, you go on to acknowledge that a phone call is psychologically more urgent than an email, and ponder how email might be extended to cover that use case...or maybe, the person was not at fault and was actually using the right tool for the job!