The hardware expense per node is very minor compared to the cost of 32 ETH, so it's a weak incentive to consolidate. Weighed against that, the slashing penalti

The hardware expense per node is very minor compared to the cost of 32 ETH, so it's a weak incentive to consolidate. Weighed against that, the slashing penalties per node increase, the more nodes fail at once. That gives an economic incentive to decentralize.