Mobile operators and ISPs have “peering agreements” to interconnect between their networks. The principle is simple: the less users/traffic you have, the more you pay for the privilege to carry traffic between your network and a Big Provider at the top of the pyramid. The more you’re closer to the top, the more users/traffic you’re carrying on your own servers, so the less interconnection costs. A similar model would work flawlessly well for Metaverse interconnection fees. At the beginning, Agni will be awesomely huge compared to every other gird popping out into existence, so that will be the most expensive one to connect to.

There is also another answer, which is that people interested in socialising with others (or open a shop, or a club, etc.) will not be able to do that from home — they simply don’t have enough upstream bandwidth.

However, I can definitely imagine people building, scripting, or creating clothes at home on their own OpenSim sims (closed to the public, except to a very small number or people, their closest friends) in comfort, away from griefers and lag issues, and pay a lower “interconnection fee” just for the privilege to upload their content to Agni. This arrangement will work quite well for most!