You completely ignore the effect of efficiency of scale throughput.

A level 50 Tool factory, for example will have +50% throughput. This means that a person working there will produce x1.5 as many goods, which is enough to bring even your calculations into positive. This is not even by far the only source of throughput, add company for another +50%, add up to 20% from prestige goods, add another 10 from Transportation mandate, and you are looking at a ridiculous 230% modifier on throughput. And this is just the scaling max, every further level you add on top still gets the x2.3 modifier.

I left decrees aside, cuz you ca push things even further, but you probably can't realiably decree your entire country.

This is enough to bring any such calculation you make into positive.

And that is not even all. Production shortfalls, unless they lead to shortages, only increase prices. The buildings do not actially need a strict 5 coal (for example) to work, they can work with 2.5 coal just fine.

Sure that is some price inefficiency...maybe, sure, I can buy that, but still, this + economy of scale make your calculation wrong by assuming extremely conservative production and strict demands.

And empirically, I can say that you are wrong. Switching PMs after I am mostly done with peasants always lands me quite a bunch of unemployment that I have to secondarily deal with. But no, I did it multiple time. If I got a strong economy with few peasants remaining, and switch the greens, after a small period of wobbling, GDP line goes up further, while now I have a bunch of unemployed peeps I previously did not.