Technology

for example, you mentioned federated code hosting or social media platforms (like lemme), in this case, you eliminate certain problems exclusive to blockchains, but simultaneously introduce other problems, like more centralisation and potential for censorship (instances in the fediverse are controller by individual ppl, who have virtually complete control over that instance, and these instances are accessed using http and dns, the former of which having little resistance to censorship and the latter being mostly very centralised), which are problems already solved by blockchains

These problems are not solved by blockchains.

Between developers pushing updates that users might not necessarily even be aware of or understand the consequences of, proof-of-stake blockchains being open to abuse due to concentration of ownership and thus voting power, proof-of-work blockchains experiencing mining pooling which concentrates effective power in the hands of people who control the pools - centralization of power effectively still remains a problem. It happens differently, on a different level, but it's far from "solved".

And federated solutions might even be more resilient to such secondary centralization simply by virtue of operating on the level of communities built around specific instances instead of the whole network.

The basic unit of sustainable human life is a village, not a singular human being. That is still surprisingly valid in the digital world. That's what blockchain people seem to get wrong.