Otherwise, if we have a lot of medium sized instances but the most popular communities are hosted on just a few huge instances, doesn’t that defeat the purpose of distributing load across many instances?
If that’s the case, how do we solve the cumbersome user experience of having to subscribe to the same community over and over again across a ton of medium instances?
You’re not putting traffic on the server that hosts a community when you browse it from another instance. Also, I believe when you post and upload an image it’s hosted on the server you’re browsing on, not the federated one that has the community.