Your passive analogy doesn't work because Gold needs to be secured and defended, which requires energy or other people are going to steal it.
Just like Bitcoin needs to be secured and defended with compute for at least new transactions. A 51% attack will allow you block new transactions or double spend coins you have, not spend or steal other people's coins on the ledger because you don't have the private keys for those.
Yes, and I believe that the total energy needed to secure and defend all the gold in the world is still much lower than the total energy needed to run the entire bitcoin network. I don't feel motivated to do a back of the envelope calculation to justify that claim though, so maybe we disagree on that point. Still, there is the material usage argument for gold that helps it maintain its value that bitcoin does not have going for it.
Even if a 51% attack only allows the attacker to double spend, that is stealing someone's coins, namely the coins of the party that you reversed the transaction on the first time you spent the coins. In addition, once people realized that double spends were occurring and were possible, it would cause a loss of confidence in the coin, causing a loss of perceived value, which then lowers the sale price (i.e. the "actual" value), meaning that the coin would not serving as a very good inflation resistant store of value.
Yep computing the energy comparison we’re not going to figure out here, but if you’re right then it would mean that it would require less energy to attack Fort Knox and take their gold. If not that means Bitcoin requires less energy. So which is it?
I’m going to store my value in the thing that’s harder to crack (which must mean it will require more energy, will it not?)
I didn't say anything about the amount of energy required to steal gold from anyone. I was talking about the energy required to maintain the ownership of the gold. These are two completely different things. If I bury a box of gold in the woods, I can then spend zero energy to keep that box exactly where it is, but a thief might have to spend a lot of energy to dig many holes in the forest ground since they don't know where I buried it. Or, more likely, they don't know who I am or that I own any gold, and the energy required to steal the gold from me is kind of infinite since they have no idea where to start, and would be required to do some sort of brute force search of the entire planet.
The point I was making is that I believe that the bitcoin value storage system burns more energy in a "passive" state, just keeping all the coins safe than the gold storage system, where security by obscurity is doing a lot of the work. As far as whether it takes more energy to mount a 51% attack on the bitcoin network or to rob Fort Knox, I don't know. That is a different and irrelevant question. I'm sure that the energy spent on the guards and A/C and everything for the building containing gold at Fort Knox must be far less than the energy usage of bitcoin, but that doesn't necessarily mean that it is easier to steal from Fort Knox and get away with it.
Just like Bitcoin needs to be secured and defended with compute for at least new transactions. A 51% attack will allow you block new transactions or double spend coins you have, not spend or steal other people's coins on the ledger because you don't have the private keys for those.