The next halving is expected to occur sometime in the first half of 2024, and no doubt you have already been hearing that the "stock-to-flow" model is predicting some grand target number. The argument goes something like this:
Current stock of bitcoin is X btc. Right now we are mining Y btc every year. When halving occurs since Y is now halved the ratio of X/Y goes up, so bitcoin price must go up. It will then be accompanied by some charts that show that over the previous halving cycles the price of bitcoin has increased.
Now take that argument to when all 21 million bitcoins have been mined, i.e. flow at zero. Working backwards you will get infinity for the price of the bitcoin.
If a model doesn't work in the terminal state, why should it have any merit now?
There are many valid reasons to attribute value to bitcoin, but the stock-to-flow model isn't quite one of them, no matter how scientific one makes it sound.