Thinking some more about this article by @aral :
https://ar.al/2022/11/09/is-the-fediverse-about-to-get-fryed-or-why-every-toot-is-also-a-potential-denial-of-service-attack/
I wonder if fediverse accounts ought to have a max number of followers as a default? This number could be changed or the limit removed by the server admin for all accounts. There could also be options for the person using the account to set a limit even when their admin doesn't, or set the number lower than the server allows.