We should not be optimising Mastodon so it can handle more people per server. We should be optimising Mastodon so it incentivises more serves with fewer people.
(And if you take that line of thinking to its logical conclusion, you arrive at the idea behind the Small Web: https://ar.al/2020/08/07/what-is-the-small-web/)
@aral What if newly created accounts get assigned to random servers by some algorythm or by giving people options considering characteristics of the account ( language, topics of interest, country/continent, etc )? Maybe even having the same account mirrored in more than one server?