Wanting more diverse experiences and perspectives is exactly why its beneficial having large amounts of people concentrated in one community. People want to be able to interact with a large amount of people, in one place where they can get the benefit of the collective knowledge and experience.

I agree, it should be transparent and decided on by the instance but think even a few beginner oriented defaults would be helpful. I think the onboarding and default lemmy experience is quite poor and anything to reduce friction for new users should be encouraged if it can be done transparently.