On what basis do you say that? Stocks could potentially involve you losing everything, and the "reward" of cutting the number of necessary doses in half is that we could potentially reach herd immunity much faster.

Bear in mind that the expectation is only about 1.9 billion doses total will be produced in 2021 - so we are talking about the difference between maybe 1/3 or 1/2 of the first world being immunized, and hitting herd immunity this year.

I'm not saying we should, the FDA is probably correct that we should follow the dosing schedule we know works rather than throwing away a whole year of vaccination efforts, but it's obviously desirable.

(it's unfair but I'm sure that most of the doses are going to end up in the US, Europe, and other western-aligned countries first, then China and Southeast Asia, and the developing world is going to get the shit end of the stick, the developed world is going to hit herd immunity long before let's say India or Africa.)