Node centralization is a lot less concerning for monero because the privacy by default nature of it makes it very difficult if not impossible to censor transactions. Even if stupid large blocksizes results in only a handful of datacenter sized nodes running the network, there's not much they could do to try to denylist particular coins.

However, node centralization does still carry the concerns about powerful actors being able to arbitrarily change the supply issuance and debase holders without explicit taxation or seizure.

As with all crypto projects fees are low and it’s fast because nobody uses it. It’s inefficiency kneecaps it at any volume.