Earlier quoted context omitted.
Twilio almost certainly has a different agreement with Stripe than is standard, and Stripe commonly bans Telecom related services: https://news.ycombinator.com/item?id=20012656 The Ubiqiti forums are also littered with ISPs that signed up with Stripe (since Ubiquiti integrates with them) used it for a few months w/o chargebacks or any fraud, but got an email one day saying they were not allowed to use Stripe. Appeals…
What business are you in? That's true that ISPs and WISPs can't really use Stripe (many use Adyen), but pure-VOIP companies offering hosted PBX and such are welcome at Stripe based on feedback I received from several people who work at Stripe. SignalWire too should be able to use Stripe.
When I asked Stripe Support about servicing VoIP companies last year they referred me to the prohibited businesses section and said:
"Historically we have seen that the telecommunications industry is one with too high of a likelihood of customer chargebacks. These need not necessarily be chargebacks in fact; the likelihood of potential chargebacks is also a deciding factor in our deliberations."