Answering your questions about "private message routing" in SimpleX network: 1. Does SimpleX protect IP addresses? Yes. 2. Doesn't private message routing reinvent Tor? No. 3. Why don't you embed Tor? Tor is great, but not for all. Read more in FAQ: https://simplex.chat/faq/#does-simplex-protect-my-ip-address
I would say the blunt argument against #TOR is latency. None of the onion routing messengers I've tried were really instant in the realtime sense of that word. Don't get me wrong. #cwtch is pretty quick while others I won't badmouth are real snails, but none s far are realtime. Disclaimer: don't trust Cwtch yet. There own admins are saying it's not ready for primetime right now. they're still waiting for their first audit, but it is really promising for the future. One day you'll have a competitor there π
4. Can I have a SMP on my home server behind a CGNAT?
I find little little difference between using TOR to message out, like for example, while in China, consider to doing it offline (which I appreciate since I'm not always connected, nor should I be to send a message). It's all about options, because developers don't always know what circumstance you'll be in to use that one feature that makes the difference for you.