in PoW the miners do not make the network decentralized. The full nodes do. Currently, some 11,000 nodes. If you had 1 miner it would still be just as decentralized.

In PoS you need to run a full node in order to mine. In PoW you can use anyone's full node.

In conclusion PoW mining will always be more centralized because you do not need to run full nodes to mine.