I think you’re overthinking this, and extrapolating limited data way too far.
For one, of course historically rich countries are going to be hosting more technology. Tech is expensive, and less developed countries are called that because they’re less developed, which includes electricity grids, internet, economic power, and so on.
Another issue is that just because a Mastodon server is hosted in a particular country, doesn’t mean only people in or from that country can make an account there. Sure, there are some servers that want to keep their communities specific to their local area, but the vast majority have no restrictions. Anyone from anywhere can sign up.
If you’re trying to figure out how to make it so historically poor countries have the most servers instead, you’re going to have to figure out how to fund and manage infrastructure expansion.
It feels like you’re coming at this with the assumption of “every country has the resources to spin up hundreds of social media servers, but they’re just not interested”, which is kind of a weird conclusion to come to after recognizing the historical impact of colonialism and the privilege differences it’s led to.