Good point. Nothing against the larger instance owners of course. If my little instance got super popular somehow (like being recommended in guides on how to join lemmy/kbin), and thousands of users got in per day, I could see issues happening just like this. I don’t know the ins and outs of tuning this software for performance at scale, and I know I couldn’t learn it fast enough if my instance faced very fast growth like lemmy.world has.
I think admins are going to need to turn registrations off periodically, as they scale their hardware (and their knowledge) to run it for more users effectively.
I think that would be worth it, yeah. Of course if you are hosting it on your home network there will be some added security concerns (and that might make it better to only allow signups to friends/friends of friends/etc). The way I see it is that some instances are going to host the largest communities, and therefore those instances are going to need to handle all of the incoming/outgoing updates to posts in those communities. Right now they can’t do that reliably and push updates out to all of their users’ devices.
So in the long run I think having small/medium instances (say a couple hundred, not tens of thousands of users) will be the way to grow. These smaller communities can push updates to their smaller user count reliably, and then have more resources to handle federated content coming in and going out. I think scaling for the incoming/outgoing federation requests would be easier than for direct user activity. Federation stuff can be queued and then spread over time, but user requests cannot be.