Elaborate? I mean mining pools in China with the oligopoly bit. Are you saying that's not a problem? I would say the current bitcoin PoW scheme is inherently seeking to end up in a few actors having most of the power due to the higher and higher barriers of entry to mining on custom silicon. ELI5 why I'm wrong?
Nodes define and police consensus in bitcoin, not miners. Miners have a single choice : mine for bitcoin according to node consensus rules, or don't. That is the only power they have.
