According to the Cambridge Bitcoin Electricity Consumption Index (CBECI), the estimated annual electricity consumption of the Bitcoin network is around 114.67 terawatt-hours (TWh) as of September 2021. This represents approximately 0.5% of the global electricity consumption.
It's the same situation as gold and gold mining. The marginal cost of gold mining tends to stay near the price of gold. Gold mining is a waste, but that waste is far less than the utility of having gold available as a medium of exchange.
I think the case will be the same for Bitcoin. The utility of the exchanges made possible by Bitcoin will far exceed the cost of electricity used. Therefore, not having Bitcoin would be the net waste.