I also agree with you in most of that, being also a firm believer about self hosting, which I have done over the years for different servers: email, TFP, web, even building my own IRC network with a few peers on four continents and a couple of servers of my own in two different countries.
I will be hosting my own relay as well, probably more than one for different reasons, being backing up of my own events and other's events I might want to also make sure I'll keep around. Nevertheless, the decentralize and permission-less nature of the protocol, unlike Mastodon and other federated systems, makes it much less critical to do it, in my opinion.
I haven't set up my own Mastodon server because I've used it very little before I was made aware of nostr and understand they are so fundamentally different that I don't really care about Mastodon or any other federated systems to even think about making the effort to set one up. If not, I probably would have done it at some point.
I also agree with you about the money, but I don't think we need Monero for anything at all. MWEB will bring a far better level of privacy and its fair share of scalability to Bitcoin, after being proven successful in LTC, as much as it happened with SegWit and LN back it the day.