Imo, people are too concerned about mining centralization. The physical ownership and operation of mining rigs is pretty decentralized (even the big miners are a small % of the network).
I would like to see a bit more mining outside of North America, and I’m also supportive of efforts like Stratum V2 to provide further decentralization assurances for transactions. So there are opportunities for improvement but the incentives generally make sense.
On the other hand, what I don’t see talked about enough is supply chain centralization. The production of the chips themselves has a lot more centralization to it. This is true for most advanced semiconductors in general (and thus is a geopolitical issue) but is of particular concern for a decentralized protocol.