Big relays and small relays will all be needed in the future. Big relays have a lot of signal, a lot of noise and a low signal/noise ratio. Small relays (specially community relays) have the potential of being the opposite.

 The idea that there will be a "centralized super relay" in the future is pretty vague and I will explain why. If there is a relay with a lot of signal and little noise which is also somewhat centralized, that relay would still compete against the biggest amplifier of signal in the entire world (Bitcoin blocks) and it would lose catastrophically because the Bitcoin system is just too solid

The paths to big relays and small specialized relays are out there. I don't see a problem in people taking different routes in this aspect and competing