Like does content get mirrored to my instance and then mine distributes it ala BitTorrent or is my instance it’s own thing?
So you need just 15 more users on your instance to break even, if you have 17 in total, you’ve saved 10 calls.
In this particular example, yes. But only if those 15 people subscribe to the exact same communities. If they don’t, the calculation gets even more complicated.
I’m not sure why exactly you’re opposed to federation when that’s one of the biggest points of fediverse.
Some people seem to be under the impression that setting up their own personal server is relieving the pressure on the network. What I trying to get across is that’s not the case, unless it’s being used by a reasonable amount of people.
I can’t tell you what the sweet spot is - but my guess would be that it’s only going to be at least several dozen, more if their interests (subscriptions) don’t overlap very well.