You can't conflate population and labor supply as the specific scenarios being discussed are cases where population was fixed but labor supply changed anyway: l

You can't conflate population and labor supply as the specific scenarios being discussed are cases where population was fixed but labor supply changed anyway: like, the reason increased population is different should be obvious... you also have more consumers (and yet, amazingly, the average wages stay the same while total output goes up, per the comment by someone else, as that is also comparing two incomparable things); but, if you do something where consumption is the same but competing labor force goes up, that allows you to isolate the two effects. (FWIW, I have no skin in any of the rest of this position, so please do make another argument against it: it is just that your statement that it is "obviously, clearly wrong" is itself "obviously, clearly wrong" as it is at best arguing against a straw man of what other people are saying.)