@kim
The federation architecture allows anyone to host a BGS, though it’s a fairly resource-demanding service. In all likelihood, there may be a few large full-network providers, and then a long tail of partial-network providers. Small bespoke BGSs could also service tightly or well-defined slices of the network, like a specific new application or a small community.
This sounds like you need a hell of a setup to actually partake in the network...