All centralized systems use less power, and you just illustrated why they don't do anything new or useful. The power backing Bitcoin secures it and is a fundamental part of where Bitcoin gains powers of economic state immutability, it's the cost of people update the state machine that secures it from spam attacks and bad actors who would try to control it - that control bankrupts them. By consuming the power it does, Bitcoin also enables the global subsidization of electricity prices (Norway's mine closures and price increases), enables the capture of emissions (see oil and gas operations generating power and mining Bitcoin instead of flaring the gas), bolsters power grid capacity both cheaper than and with less environmental damage than batteries (Texas), and subsidizes predominantly renewables infrastructure by absorbing dynamic loads (China).
At first yeah less resources anyway, I wouldn't just say power. But in terms of growth, centralized systems expand and consume more power at a rate more than linear.
Banking lets say as an example, if you open one branch with one vault, requires certain staff, security, insurance, overhead etc. Two branches maybe same, but 20 branches, you have new additional staff, more security, more overhead, everything grows bigger than linear.
Bitcoin will always cost more as it grows yes but the value keeps up. And it will never need more staff, more overheads etc, in fact while more computer power is needed to secure it, the value grows along, but the efficiency of miners get better.
Thats my take anyway when people talk about BTC cost.