Fair points and a very well constructed argument.
Thanks.
The thing is, how do we ensure the security of a chain without wasting this much energy? I mean, if we don't care about the decentralized aspects of Bitcoin then we probably shouldn't be using it after all. So since we do care about its decentralized aspects.. how do we make this possible?
Since there's no known better technology than Bitcoin/PoW, this is simply the best we can do. There is enough time for open-source to be explored and to make Bitcoin better as time goes on. But the issue is, the Bitcoin community generally doesn't like changes. Therefore, even if we did find a better alternative to PoW, chances are it'd be instantly rejected by the crypto community.
This thing is double-edged. You have a currency that needs upgrades but upgrades mean acceptance, which this particular community doesn't agree with very well.
The simple answer is that, you don't. The very fact that people are highlighting that Bitcoin has been consuming tons of energy means that it is working. PoW is working because it is prohibitively expensive and unprofitable for an adversary to attack the chain. We don't have to change something that is working.
The only thing that has to change is people's arguments towards Bitcoin's electricity wastage. Yes, Bitcoin consumes a ton of electricity, and isn't as efficient as other payment processors...
But, there is a potential for it to eventually scale and serve as a substitute for the financial systems around the globe and as a universal payment processor at the same time. It simply doesn't make sense for Bitcoiners to refute the arguments by deflecting it to:
1) Other issues, ie. non-close substitutes.
2) Renewable energy; Doesn't mean zero environmental impact, doesn't mean zero e-waste, doesn't mean zero opportunity costs
3) Some ridiculous arguments which has no relation whatsoever to the issue at hand.
My point is that it is simply better to embrace that Bitcoin is an inefficient currency right now. Trying to refute the said arguments with the points above just makes us look like fools and cultist.