Exactly, the easy access and low barrier of entry (like reddit, twitter, etc.) make it perfect to populate. That’s kind of why some of the instances need signups right, to keep out the riff riff?

Not sure about that. Even if .ml was open to new signups, there are quite a few reasons people would pick .world over it:

1. .ml goes down more often than .world
2. .world allows non-nudity NSFW content, while .ml does not allow any NSFW content
3. A lot of people have concerns about “tankie” ownership of .ml (whether that’s true or not), while the owners of .world seem more politically neutral

I got in before signups were closed, and have accounts on both .ml and .world, but have abandoned my .ml account for the above reasons