How would you make cryptocurrency more efficient?

My knowledge of this technology isn’t very deep. From my understanding, mining is essential to facilitate transactions, which in turn makes cryptocurrency a currency. Mining needs computing power, which needs energy. More energy translates to more rewards, which incentivises parties to keep mining and keep the network running. Even if you make the underlying calculations more energy efficient, miners are still incentivised to spend more energy to capture more of the reward(?).

Agreed, but that is complete a different matter to the comment I was responding to. The point is that people don't understand why PoW is not going away because they don't even understand the value proposition of PoW cryptocurrency.