Mastodon has some structural problems, and instances do not scale well. Mastodon.social is run by Eugen (who created mastodon), and he's had to disable core fea

Mastodon has some structural problems, and instances do not scale well. Mastodon.social is run by Eugen (who created mastodon), and he's had to disable core features of the service (local and federated timelines) just to cope with the sheer number of users. AFAIK, it would take significant work to rewrite the software such that it scales the way Twitter does.