Ik I'm late to the party, but I think this would be soooo much better than Wikipedia for finding useful information on niche or controversial topics.

Instead of being limited to Wikipedia's contributors and having to accommodate or guess their biases, and have a terrible, incomplete "controversies" section on every page, you could browse the same page across instances whose biases are much more explicit and see what each group determines is most important about the topic.

Instead of having to find a single mutually agreed upon article where each "faction" has their own set of issues with the content, you can now browse pages that each of those factions feel best represent their POV, and use the sum of them to form an opinion where no information is omitted.

Obviously lots of instances will have complete bullshit, but it's likely enough that you will find instances that have well-sourced material from a diverse breadth of viewpoints, and can pick an instance that federates to your preferred criteria for quality. Misinfo will exist regardless, and if they get it from a federated wiki, it will probably be at least marginally better quality or better cited than the Facebook or Reddit posts they were getting it from before.

It would be useful for the "what does X group think about Y" aspect alone.

There's also nothing stopping diverse, consensus-based instances from popping up. Or lots of niche academic instances with greater depth on their areas of expertise.