I went down that rabbithole when I had to set up Graphql with federation. The reason it seems complicated is because they're attempting to fit bootstrap processes of different libraries into their own IoC style by writing tiny wrappers.

You end up with large blocks of config in ugly decorators but what they're doing is trying to supply that config to the underlying libs.

I consider Nestjs docs to be among the best written docs in the node community. Virtually everything you need is in there.