Ultimately instances with more users are better able to collect donations and reduce per-user monthly costs,
Everyone has their reasons for defending centralization. For you it is cost savings, apparently. Money wins, unless the tech is done well.
(edit) Small instances are cheaper to secure because they are less prone to targeting. The bigger an instance gets, the more it costs per user for infosec.
it also wouldn’t be good to have them spread out evenly across 1,000 instances.
It would be good, but not for the bottom line. Facebook has mastered the bottom line indeed.
Without a mechanism for user data to be completely transferred between instances (including post and voting history), an instance shutting down is a terrible experience for new users that could encourage them to return to a commercial social media network and must thus be avoided at all costs.
It’s a problem for sure. Lemmy devs are pro-data portability, but they give it a low priority. They hope that someone will build a bot that ports data so long as it does not require Lemmy server code to be written. IOW, they (Nutomic specifically) calls for a hack job. He posts pseudocode here: https://lemmy.ml/post/31128657/19022698