You cannot prevent power centers from leveraging their influence, but with federation you can route around it.

They only list instances that share their principles. The only “forcing” being attempted here is the two of you insisting they need to list instances they don’t want to list. The point of federation is that you can start your own list if you don’t like their policies.

The nature of federation is that you can make your own instance with your own rules independent of a single walled garden and still participate with the other members. Create your own index if you don’t like this one.