Believe it or not but the entire development with ever more efficient hardware was anticipated already when Bitcoin was conceived.
POW is incentive based with greed as the driving mechanism and that is what makes it work. It's up to the blockchain projects to find technical solutions to problems with centralization. Social engineering as a solution can work short term but is not likely to work in the long run.

Luckily, it is comparatively easy and cheap to do software changes compared to develop new hardware. A blockchain project interested in keeping a certain type of hardware away should not have no problem doing so if there are competent developers.