Great points. I agree it's not perfect, but each user could tune how much they want to slow down spammers vs not see valuable content. I like the upfront PoW cost as a further hurdle and I like the WoT / meet up layers as well. Maybe some of all of it. I suspect there is no silver bullet, but also that real Nostr users who put in the effort and PoW should have better visibility. Interesting about Gel's comment that this can turn into an elite club. Real world example in Club House.  

It will be fun to see how this evolves.