The current system does not rely on nodes time but rather the block timestamp which is a part of the block template itself, even mainnet does not use node time any block verification, even in the 2 hours rule which is not a part of the consensus (contrary to what most people think) uses network adjusted time ( not node's own time) and even that does not invalidate a block.

If you were to rely to nodes time then sybil attacks would be very effective, PoW is important, you find the block first then we know if it took 20 mins or not, not before.