Yes, you’re wrong. Partly because you’re forgetting the fact that “increased technology” comes about essentially because of increased population. You’re falling into the common trap of assuming every human being is just a mouth to feed, a drain on resources…as opposed to a contributing resource in himself.
Don’t forget, increased productivity (and by extension, increased standards of living) come about through capital accumulation and division of labor. Lessor populations just don’t have the capital — and they certainly can’t divide up labor — as much as greator ones…
As for Mises, I see nothing in that passage that even implies he shared Malthus’ doomsday views that “human population growth would outpace food production—and fast—which would lead to societal ruin.” In fact the last line of your quote states: “the role to be assigned to them within the body of the sciences of human action is different from that which Malthus attributed to them”…showing Mises did not agree with the way Malthus applied his model.
Those comments of Mises are made about Malthus’ law of population…not his prophesied catastrophe. The law, to my understanding is simply “an approximate physical law as it is generally acknowledged that nothing can grow at a constant rate indefinitely.” And as Wikipedia points out, Joel E. Cohen has stated that the simplicity of the model makes it useful for very short-term predictions and of not much use for predictions beyond 10 or 20 years.[4]