This graph is actually wrong, lemmy.ml doesn’t have open sign ups, it just appears to because the Lemmy software doesn’t accurately distinguish between open and closed registrations, it only distinguishes between open registrations and application-based registrations. If registrations are closed it’ll look just like they are open, but we’ll just give an error message when you try to sign up which is incredibly deceiving.

I filed an issue to fix this discrepancy on their GitHub.

Another issue with this graph is that it shows lemmy.world as American but it’s actually hosted in Finland.