but it has brought enough progress
No, it didn't. It's very easy to see progress in the short term if you are sacrificing the long-term. The "free school for everyone" was not really free, it was sustained by the Commune taking resources from outside, but sooner or later they would run out of Other People's Money.
Then maybe we shouldn’t try to have large-spanning entities.
Yes, agreed. This is one of the reasons that I don't like to see the Fediverse as a bunch of "platforms" and would prefer to have it working as a proper decentralized web.
Just like internet services.
Internet services only work because everyone speaks the same language/protocols, which is only achievable with a large centralized authority, or with a network where peers do no trust each other (blockchain-style).