I think this would be immensely helpful for niche topics, but I don't really see it as much of a direct competitor to Wikipedia. Interwiki links have been a thing for a long time, but they're not really used that much. They also are used by specialized shortcut syntax instead of using a more intuitive domain name syntax. So let's say you have a wiki for the Flash TV show and you want to link to an article in the Flash comic wiki. This would be great for that. Maybe have "search related wikis" as an option to search some hand picked wikis?

But for going head-to-head with Wikipedia, I don't really see it so much. Part of the success of Wikipedia is that it forces editors to work in a single namespace, debate the contents, use a common set of policies, and so on. There is also a lot of policy, process, human knowledge, and institution built up over the years geared solely towards writing an encyclopedia. If you go to Wikipedia, it may not be perfect, but it will have gone through that process. Trying to wade through hundreds of wikis to find a decent article does not sound like a treat, especially if effort gets spread across multiple wikis.

Like with Lemmy, I am excited to see where this goes. And nutomic, congratulations with your daughter!