So if I understand this right, you pick a server and your server account can post on that server and any servers that that server federates with.
So what happens to your account if the server you joined goes down? Yes, you could always create a new account somewhere else, but you lose all your followed communities and post and comment histories as well.
SSB would be great if joining it was simplified. Nostr’s problem is one of moderation. Online spaces all moved to having moderators to protect users from an onslaught of hurtful content constantly and with Nostr you’re all on your own to block each. Individual. Harmful poster you don’t want to hear from anymore.