With reddit we mostly had a single subreddit for a given topic, for the sake of the question let’s use gaming. If there were alternative subreddits dedicated to the same topic, they had names that gave that away. Do you think Lemmy will lead to more segmentation, and more information bubbles seeing as we now can have gaming@x and gaming@y without a obvious way to see which community is the “default” one? Will it be a good thing, as you can find a community that suits your preferences better, or will it stifle discussion?
And if the whole MTG community is subbed to all 10 of the different MTG communities, and participates in each of them regardless of instance… where’s the problem? And the if one mod goes on a power trip or one instance crashes, the other duplicate instances will just fill the void. Of everyone is still subbed to the duplicate communities, I can only see this as a positive.