if PoW changes.. then it is just backdating security of bitcoin temporarily and in a few months the pools will be back where they are at the top but this time with a new asic/machine to make block creation more efficient than 'solo mining'.

EG if it went to a 1node 1 vote.. pools will simply make an asic/machine that acts like several clustered nodes syndicated together.

end result is just a couple months of drama until things are in the same position as now.

edit: (couple seconds running scenarios in my head)
infact less than a couple months. because the time it would take to get majority node acceptance of a new mining algo/difficulty/hashing rule..
pools would have the time to design the efficient solution to be ontop right when it activates.. thus solving nothing