PoW coins are not backed by energy, this is a total misonception. PoW currencies are secured by their spent energy, while PoS coins aren't really secured by anything - if you hold enough coins, you can attack the network as much as you want, compared to PoW where it would always cost you money to do so. But simply having PoW does not guarantee security, you need a decent amount of energy involved, otherwise it's still practical to attack such coin, which is what you can see with coins like ETC or BTG which were successfully attacked in the past.
The total expenditure of energy to guarantee the functioning of a cryptocurrency is not comparable to what is spent to maintain the functioning of the current financial system. Nothing in the real world works without expending energy. This is also a misconception.
It is important to note that with PoW coins you cannot simply create 20% of your total coin supply out of thin air in a given wallet saying that it is the "project's foundation and/or the for the developers and initial investors". Who will invest in an excellent project knowing that 50% of the token total supply is in the hands of the developers? It seems to me that this is an important problem that calls into question the viability of a project, no matter how interesting an technology is. It seems to me that this is exactly what prevents "ethereums killers" from actually killing ethereum. PoW coins are at least more fair and decentralized in this regard.
Pow or Pos don't matter in terms of coin value, what matters is the actual utility of the coin, with pos anyone can stake the coin and benefit from it but pow is not always that simple, beside many projects are only going for pos now.
Ok ... I would like to go deeper into this topic, but I would like to make it clear that this is already deviating from the OP of the discussion.
I think that we (participants in crypto space) need to reflect on our role in this technological revolution.
1. It is one thing to put ourselves as an investor, looking for the project that will increase the price of the token and make us profit from it.
2. Another thing is to look for the project that is useful and is better developed.
Note that finding a project from point 2 does not necessarily mean that it will be the best project in terms of investment (point 1).
Bitcoin is originally an "electronic cash" project, but it cannot be used to buy coffee. For this purpose (eletronic cash), other projects are better: bitcoin cash, litecoin, monero, digibyte, etc.
Like other smart contract projects, they are better in terms of scalability than Ethereum, but they simply cannot kill the ethereum, however advanced its technology.
This reflection questions our (mine too) idea that the project is valued for its usability. It seems to me that there is a certain conservatism in crypto space, which simply prevents us from moving from one project to another with better characteristics.
And this is absolutely predictable ... noticeable in so many other technologies. For example, Whatsapp. It is not the best instant messaging application, but it is the most used because it was the first.
The new question I ask here, changing the direction of the OP a little, is: do we all know what our role is in crypto space (investor or users)?
Because if you are a user, it is better to use digibyte (a heterodox option, to generate less controversy) than bitcoin as electronic cash.