It will not come to that point. There will never be a Bitcoin shortage. The value of Bitcoin could adjust up to whatever point it needs just to satisfy the demand and the necessary valuation when the entire world will be using Bitcoin. If the demand is rising so high due to the billions of people across the world using Bitcoin, the market will be assigning a bigger value to every Satoshi. There are eight decimal points in every BTC. It may happen that .00000005 BTC will be valued 1 USD.
A good point.
Just to add, if the demand will constantly increasing, the circulating supply will be the same as halving is the one responsible for this. The last bitcoin will be mined by 2140 in which new bitcoin that appear every year will decrease. So even people are dying to own some when there's just limited bitcoin in every year then they will have nothing to do but to buy even it's damn expensive. And there's no way to have a shortage in bitcoin hence people who hold bitcoin now is fortunate.
And having a finite supply, as so their scarcity increases.