Things can be valuable without being profitable. A hug from someone you love does not generate any profit but is still a good thing that should exist. Likewise, a community resource like a Lemmy instance does not need to justify it's existence by being profitable. It can simply exist as something that people get value from. The fact that we often lose sight of this is a result of living in a capitalistic society that over-emphasises the value of something producing profit and underemphasises any other possible value. As for the implied question of, how does a Lemmy instance get the money to pay the costs required to run it? That's going to vary from one instance to another and how that money is raised should be a factor in which one you sign up to and which ones you connect with. In the case of Lemmy.world, it is, afaik, presently (and likely in the future) run as a non-profit for it's own inherent value and is funded by user donations. A big point of federated communities is to allow those communities to be able to operate for their own benefit, rather than be reliant on commercial investment that will later create a tension of different incentives.