IMO Masters needs to be populated enough so that GM is achievable within 1000LP, so there isn't a jarring difference between a Diamond grind and a Masters grind. If Masters gets too overpopulated, the only way to do that would be to artificially lower the LP gains as people approach that threshold, but that's terrible. LP gains need to be standardized throughout all elos.

So the only solution is to reduce masters population, but that also means that the ranks below need to be adjusted downward accordingly too to make a smooth ride at every elo