Then you have not understood it. High gas prices are not evidence of high cost (as in the cost to the network to settle the transaction). In a bit analogous way high price of a luxury item is not evidence of its high cost of production. But instead of its desirability with respect to its abundance.

Cost and value are two different things. Ethereum blockspace is in high demand with respect to its supply and that drives its value (gas prices), and this is irrespective of its cost to settle that blockspace (energy consumption, HW costs, etc...).