Yeah, it's sad. They started as simply an SMS gateway. I still have a Twilio account, for my steampunk Teletype setup. It's a pure reply system - you text to a phone number, that's printed on a Teletype machine, and the sender gets an acknowledgement back. It's inbound SMS. Years ago, at Twilio's request, I demoed this at a Twilio convention. Twilio now wants me to "register my marketing campaign" and pay an addition…
they still support pure request reply, but that has become commoditized. there’s a bunch of sms gateways to choose from today. so twilio is finding the most valuable forms of sms and productizing them. this is classic growth steps for a 15 year old business. aws has been doing this since before twilio was founded
Disclosure: I was at WhatsApp from 2011 to 2019, and worked on SMS and Voice verification. We started using twilio as an alternative voice provider, and only later added them for SMS.