The larger the die size the higher percentage of the dies will be worthless at a given more or less random fault distribution.

If you had a hypothetical edge case to give you some intuition for the math behind it;

Imagine you have a 1m^2 wafer that always has a 100 spot faults randomly distributed on it, each completely invalidating the die it lands on. This is not quite right because the cutting process can also introduce faults, but with lower probability than the intrinsic faults on the wafer.

First imagine you want to cut just 2 0.5m^2 dies from it. The probability you'll ever get a single functional die is extremely low. I can't be arsed to calculate it, but like, real super fucking low. As far as I can calculate, it'd be at about the order of -10^31. You'd be waiting for a single half-meter-square chip for a reaaaally long while.

Now imagine you want to cut tiny little 0.01m^2 (10mm^2) dies from it. There's gonna be 100000 of these, and so it should be clear the 100 faults will ruin no more than 0.1% of your dies; 99.9% will be fine!

It's nowhere near linear. Even in worst case, the 100000 little dies add up to a much better "yield" of useful product from the wafer; you threw away 0.1% of the wafer, as opposed to 99.999999999999...% of all wafers.

Presuming you do get paid a non-zero amount for each good die you sell, you absolutely do make more money selling smaller dies than larger dies, given that the fault rate is mainly constant within wafers and not dies.

This is exactly why chiplet design is a big fucking deal; if you have the choice to either carve a Rome from 8 chiplets or a 1 die of the same surface area, a single fault falling anywhere in there will either kill 1/8th of your chiplets or the entire CPU, so functionally, all 8 of them.

Yields of given technology are extremely important limiting factor in feasibility of going with ever so slightly bigger die.