I still do not see how a simple tool to transaction accelerator could lead to "centralization". Nobody is forcing you to use it. Also there are many others miners that are doing this and from long time not just now.

In the future, I see the coming of so called "scrap miners", the ones that are willing to include in a block those txs with low fee and in exchange for small amount of sats, paid directly to them, user tx could be pushed to a block that they are trying to mine. But in the end this is just a lottery, you never know if they have enough hash power to mine that block with pushed txs. But if they have that luck, so be it. Why not?

This will increase the challenge on the fee market and that is good, all those greedy miners will be forced slowly to accept low fee txs.