Yes, we can say that bitcoin is energy (not work, that’s a misconseption in physics terms), but it’s also applicable for every other fiat and shitcoins. Entropy is what differs bitcoin. Due to the arrow of time, no one can bring back the energy you spend for any spesific work. Sometimes, work can be undone, but with consuming more energy. That’s the magic of the entropy, it makes reliving the past and undoning a work impossible.
Bitcoin uses PoW mechanism to back your time and energy with entropy and that makes the value of your efforts immutable.