This question is answered rather quickly when you ask two questions: 1. What exactly are people paying for? 2. Is that actually necessary for messaging? If th

This question is answered rather quickly when you ask two questions: 1. What exactly are people paying for? 2. Is that actually necessary for messaging? If the answer to 1 is servers, the answer to 2 is no: distributed or federated messaging is entirely reasonable and possible to do. If the answer to 1 is paid developers, the answer to 2 is no: there are plenty of developers willing to work on open source. Try it.