Now, if I were to sell you something you cannot live without, like water, the base value constants become the supply and demand and the work I need to do in order to get to that water, get it out of the well, bottle it up and deliver it. This becomes a minimum in price.
We don't disagree, I'm just pointing you out that it's not the same with Bitcoin, because those sudden drops in either the price or the required computational power can redefine the cost.
If 1 BTC is valuated at $40,000, but there's a sudden Chinese black out which affects lots of Chinese pools that contribute by owning a significant percentage of the network's hash rate, the cost of producing 1 BTC will decrease once the difficulty re-targets. But, the price has no reason to change, because the supply has remained the same (it's inflating by 6.25 BTC every ~10 minutes) and so is the demand.
Another example, but with change in demand: If there's a intensive trend of selling, which essentially causes drop in the demand, the equilibrium price will decrease. This, as a consequence, might discourage some miners, temporarily, to continue mining, because their income might have dropped by a lot. It is reasonable to assume that the cost of production remains the same, but it's not. In the next difficulty epoch, difficulty will lower which will decrease the cost.
I can see where you are going with that and what you are trying to tell me however the real question here is whether or not Bitcoin can go to 0. And the answer is no. Because it has an internal value which cannot be denied.
Even if the apocalypse started in 10 minutes or in a long long time from now and nobody wanted or needed Bitcoin anymore in such a reality, nobody would sell it for $0. Even if all hope was lost, they would hold on to their coin in hopes it would rise in price again.
The minimum price, even if it is a low low price, it would still be the minimum due to the minimum effort/money/goods you would have to put in to create a Bitcoin.
Now if EVERYTHING including energy became absolutely worthless in the world, then the base price of Bitcoin would become 0. But thats unrealistic, don't you think?