The redundancy is somewhat the point. While one instance may have a dominant version of a community which is visited by people of numerous instances, other instances having local versions promotes decentralization, and helps smaller instance form their own culture.
The decentralization is good because it ensures a single power mod, cabal of mods, or crooked admin situation can not unilaterally ruin everything. Users can just jump ship to a different community that is run by different admins and mods.
Smaller instances having spaces where their own memes and in-jokes is good to create a culture for that instance to help give some different flavor and helps that specific instance grow. This feeds into supporting the variety of smaller communities on that instance, allowing them a chance at traction rather than existing in a void.
If you want both communities, just subscribe to them both and let them appear on your feed.