- could Lightning decentralisation be improved by giving node operators a "do not route thru X" config option?
- could the obverse be achieved by allowing clients to preferentially route through nodes with some definition of "fewer" channels?
It might improve decentralization but it would be less-efficient. The reality is, hubs/specialization will always form for efficiency, and a smoother UX. But it's OK, because anyone can be a hub themselves, plus users can always circumvent the hubs, anytime.