Things only have value because we agree they do. The US Dollar is backed by the full faith and trust in the government. "Faith and trust" is as much a digital tulip.
If bitcoin could solve those problems, and the energy usage problem, I’d use it. As is, it’s solved the double-spend problem - admirable and impressive, but it’s not a substitute for a stable currency yet.
Second, you have natural scarcity: truffles are not commonly available. How much you want to eat them may put a ceiling on the price, but again there is also a floor below which no amount of energy would bring you more truffles.