This would require a whole lot of discipline, namely the discipline of everyone always adding all appropriate tags to their content. In a Fediverse which most people use like Twitter/a Threadiverse which most people use like Reddit where there simply are no such tags.

Even if there was a *booru clone in the Fediverse, you’d still have shit-tons of people who upload their stuff with literally zero tags whatsoever because they can’t be bothered. Just like on every last already existing booru.

No-one is willing to build Fediverse software upon discipline as a requirement.