The cool part about this is that when Marx theorized about it, there was no reason to make this kind of prediction. It was so early in capitalism. Its honestly on the same scale as when Einstein said GR predicted light would bend around the sun so the apparent position of the stars should change, so they checked during a solar eclipse and he was right. Same deal with the tendency for the rate of profit to fall, it took a while but the evidence is empirically there.
The cool part about this is that when Marx theorized about it, there was no reason to make this kind of prediction. It was so early in capitalism. Its honestly on the same scale as when Einstein said GR predicted light would bend around the sun so the apparent position of the stars should change, so they checked during a solar eclipse and he was right. Same deal with the tendency for the rate of profit to fall, it took a while but the evidence is empirically there.