yes i think pow relays will be a thing (i believe #[4] is waiting for a client with POW to implement one). pow relay will likely have less spam. but also pow for feed filtering.

having client handling media is exactly what I want to avoid as I feel that it is a centralizing factor. I have been building a selfhosted media server that authenticates by nostr credentials and theoretically can integrate with any client. it also can be stood up as a 3rd party service to astral (or any client). this would also allow you to switch media hosting providers without having to switch clients. but unfortunately haven't had time to work on this lately.

other interesting aspects of this media server are content signing (file name will be hash of content, so if the file served is later changed anyone can tell) and perhaps torrenting and easy re-seeding of media.

lots of ideas, not enough time