Any system that relies on specialist groups to supply a fundamental feature or infrastructure will always yield centralization coalescing around them.

To fix the centralization you need to remove miners as a group. Mining has to be a by-product of using the system - users are the miners. The more users there are, the more mining takes place, transaction throughput increases and security strengthens. Not as it is now - the more money you have, the more mining you can do and users are just an advertizing strategy for their service.

Unfortunately Satoshi designed the Bitcoin system to be centralized. He/she even spoke of centralization in countries where electricity was cheapest or could have been offset against the heat generated. Bitcoin as it stands is destined to be purely data-center driven and owned probably by government backed corporate interests (aka banks).

I don't have any answers to this. The system as it stands was not designed to resist centralization and economists will drive the design towards centralization so it can be monetized just as the internet has been.