What is the barrier of entry for starting your own relay?
From my understanding it is doable. If a relay becomes oppressive or undesirable customers will purchase elsewhere. Centralization doesn't happen here IMO.
Why do you think it would?
Discussion
The same with crypto. Network effects need as much people and on a central platform. Bitcoin solves this by creating incentive to be on that platform, but Nostr has no such thing as that and to be fair, it would probably make it worse.
Message propagation sucks for me, 19 relays connected. Cant load many comments fast, many post not founds and also lost posts of weeks ago.
Fairly low for personal relays, although you need the technical knowledge. There are services out there that will handle that part for you though