Discussion on Bitcoin’s energy problem

In a world where saving energy should be our highest priority why use Bitcoin (that has an enormous energy impact) in comparison to possible alternatives (based on PoS or other consensus algorithms) ? Is this sustainable ?

I know some people may say Bitcoin is more secure, more decentralized etc, but is this reasonable ? Bitcoiners are dreamers of a new monetary system so shouldn’t the low energy consumption of such a new system be a condition sine qua non ?

I would like to hear some arguments on the pro-Bitcoin side :)