Even Twilio has a hard time with deliverability of SMS due to spam blaclisting by carriers. There’s a reason why SMS delivery is so expensive, and why alternatives like WhatsApp want in on the action.

Twilio runs into the exact same text deliverability issues in the USA that everyone is experiencing, there is no reason to pay them a premium when they have no ability to influence. Whether or not your text is caught by AT&T, Verizon, T-Mobile, or US Cellular's spam filtering.

Avoid sending SHAFT content and shortened URLs if you don't want to get your text messages. Black hold or banned. S.H.A.F.T. is an acronym that stands for Sex, Hate, Alcohol, Firearms, and Tobacco

Exactly, carriers have no way to know if a SMS comes from Twilio's legitimate or less legitimate clients, so they have to block everything. SMS is no longer the cash cow it used to be so tehy can't afford to spend lots of money on individual message moderation and have to adopt more crude blocking measures.

They should also add crypto to the list.