I think the far-right “manosphere” influencers are a good indication at what it does to mental health. Fascism, and extremist groups in general, seem to thrive on men not getting laid. IDK what the cause of this is though; I suppose more digital, less IRL social entertainment. They drink and do less drugs, which could be a reason too (especially drinking).
Edit: This is a self-reported statistic too. It may just be men are more comfortable reporting that their virgins instead of lying.
If doing an overlay network (network on top of the Internet), you probably won’t be able to do much better than Tor or i2p.
https://freedom.cs.purdue.edu/projects/trilemma.html
This applies to all types of anonymous networks as well (BT, Wifi, etc).