It is one of the reasons I appreciate masto.host as the owner has made it clear that signups are gated in part by how much of the fediverse it collectively host

It is one of the reasons I appreciate masto.host as the owner has made it clear that signups are gated in part by how much of the fediverse it collectively hosts, because they don't want to be a central point of failure, they do want to encourage competition, and they also don't want the headaches of running that big of an instance population.