I think you over estimate federation, I started and ran a federated wiki and it's attached company in ~2008-2014 for a particular niche because I am very pro-federation but it's not a panacea and can lead to generally worse alignment with reality.

This is like a monolith vs micro services debate all over again and it shares a lot of the same issues and tradeoffs since we're talking about network efficiency, validation, throughput and error handling in systems generally.

Federation fosters fragmentation and discovery issues that means unless you have a "reality reification" process a centralized but transparent and public system sees very little benefit from federation.

Having a trusted (due to transparency, not perfection in data) and transparent centralized source that trends towards "true" is almost always more efficient than federation, but people seem to hate the idea of rules of governance, this makes sense, as anyone who for whatever reason disagrees with the content on wikipedia will push for fragmentation to push their position closer to the mainstream (which may very well be "more true" for a specific topic) even if the fragmentation damages accurate mapping to a shared reality in general. That's why good governance processes must include "dissent from dissenters in their own words". We must have a "good enough" in content and accuracy system that is the globally agreed on place for us to "fight" over propositions, this allows us to all be on the same page even if we disagree and to share a map of the disagreement space.

Independence is not the same as governance, they are orthogonal and people who conflate this clearly haven't thought this through. Just look at denominations and churches for historical repercussions of the different approaches towards governance, excepting a very narrow subset of polity beliefs if you go to attend a "baptist church" or "bible church" you have NO CLUE what they believe or even if they are in fact a koolaid drinking death cult. I think this is good but it is very inefficient, so even in these types of denominations groups will join "conventions" to signal their belief... even then it's buyer beware.

There are a lot of young earth creationists, flat earthers and corporate and political shills of various stripes who sounds plausible to those ignorant of the subject who HATE wikipedia. This hate is a sign of a generally healthy ecosystem.

I think a lot of people and state actors are incentivized to denigrate anything "imperfect but auditable" as being bad, the simple fact is that humanity needs "Trusted" sources, not in the sense that they are perfect or accurate but in the sense that this platforms goal is "we're trying to align with reality as hard as possible" and we have a globally recognized and shared space to do so, which means dissenting voices will be observable in Talk pages and we ultimately have a jumping off point that has a "shared nomenclature/history" people can fight over.

People assume small players are inherently more trustworthy. They are not.
Some people assume contrarians are inherently more trustworthy. They are not.

Big is not inherently more evil than small. Transparency is the core to error correction either way. Most federated systems as implemented today seem to reject transparency outright which is totally screwed up and worse than a "open" centralized system.