IMO, Lemmy would gain far more users if you were able to create a user account without having to be approved by a server first.
If communities want to remain invite only that’s fine. But I really, really think you guys should decouple account creation from the requirement of being approved by a server. It’s a barrier to entry that imo will prevent many users from registering.
Edit: If not global auto-approving of user account creation, I think what would be a more reasonable request is an indicator of whether a server auto-approves account creation or whether it is invite only.
If by main network you mean the largest federated network (the largest number of federated instances together), then it is precisely that.
It is then up to each user to decide where to create an account. On any single instance? On multiple instances where some might be federated with only a small subset of instances and others might be more general instances federated with multitude of instances, for example on the largest federated network? It depends on what the user comes here looking for. Whatever works for them is great.