Because it's better in term of health of the fediverse if we don't end up with only a few big instances like lemmy.ml. Also people can interact with lemmy.kde.social while not being on that instance
Do they need to approve each and every instance manually? I thought it would happen automatically as soon as someone is trying to subscribe to a "channel" of another instance. No?
I'm not familiar with the exact process yet. But doesn't that mean if you wanted to run an unfederated instance, you'd need to manually block every other instance there is?