If everything else fails, I know I can still have two things to pay with: cash and crypto.
Bitcoin doesn't store any energy.
Bitcoin is like a F1 car going around a track forever, with your name scribbled on it.
I think of them as representations of the idea that energy is (currently) so abundant and cheap that we can waste it on mining things like gold and crypto, a fundamentally ridiculous concept in terms of real actual human needs.
Once that stops being the case (when fossil fuel starts running out globally), the whole thing - cash, gold, crypto, stocks, bonds, property - everything falls apart.
Bitcoin is valuable because people accept that it’s valuable, same as with cash, gold, crypto, stocks, bonds, property. The price of an apple is $2 is because I offered it to you for $2 and you bought it.