I don't particularly agree that it's "greatly increased" by it. I'm on a server with them and I don't see that much many more spammers. It seems like fearful hyperbole, I'm not saying there aren't any I've certainly seen a few but it's not as common as most people think it is.
My mastodon instance rarely ever sees spam despite having open signups either. Maybe my problem is I’m worried about future problems rather than the current state of how things are. My concern comes from personal experience with legacy socials like facebook and twitter when it comes to spam that I report and the frustration of when I get the automoderation notification back and they determine it didn’t break their guidelines.
I don’t want the cesspool of spam to become a problem on the fediverse as these experiences were a major reason I decided to join it.
I appreciate your comments again. You’ve softened how I feel on the challenge of balancing open user sign ups with moderating malicious users.
I’ve read over the documentation a few times and maybe I’ve missed it somewhere else but I’m not aware of any option to host a relay yet. As far as I know only self hosting PDS’s are an option now (which only handle your own data and authentication but still relies on a relay to serve you content from the rest of the network) and app views (which are the front ends that sort and show content)
So in a sense bluesky is distributed and portable within the ATProto network, but still centralized until other entities can host relays and interopt (or opt out of interoperability) within the network.