There's also the argument that people should get used to the idea of not being force fed from one source/community/etc. Redundancy also has its perks.
Lemmy's greatest strength is also its greatest weakness imo. The decentralized nature makes it much less intuitive to navigate and use when you're new because it just works differently to what people are used to and commonly expect.
Having multiple communities isn't a problem if they aren't dead imo. The problem is a user base that doesn't have a native way to easily access everything on the fediverse (or even Lemmy) from whatever instance they register on. That leaves us with users who simply don't know any better when they look for communities with a local search and can't find them.
I think we need to work on retraining people to search using tools like lemmyverse, or find a way to build its functionality into the default Lemmy search. Consolidated communities only help if people are able to find them reliably and many of the users are brand new and struggle with the transition.