The amount of power wasted by BitCoin indirectly depends on the monetary turnover of the system. Because if somebody can spend $1mln to perform 51% attack and move around $1bln, that will likely be done. Hence, the power wasted is proportional to the turnover of the system. Otherwise, it does not work.

Also, when a bank charges me 1% for a wire transfer, they pay salaries from that money and some people buy food. The power burnt by BitCoin is actually literally immediately irrecoverably physically wasted.

You could do it with an increase in the block size, but the Bitcoinsphere has bitterly resisted all attempts to increase the block size.