a common argument for population maximalism ("population growth is good") is that "more population means more Einsteins", ie. "more population, means more geniuses that advance progress and make the world better for everyone"
(it's also echoed in pro-life arguments: "the baby you aborted could have been the next Einstein!")
this view purports that the primary thing missing from progress is more highly intelligent people, and since intelligence is pretty much biologically random, we just need more of them
but...
this may be just another incarnation of "great man theory" (singular individuals creating jumps in progress, when really, great theories and achievements are built piece by piece, with credit often going to the one completing the last step)
the systems in place may have a much bigger role than the "input quantity of intelligent individuals"
ie. the odds for a "genius" to "create progress" aren't constant
transplant baby Einstein or Newton (or "insert genius here") into an impoverished family in a war-ravaged country and see what you get
or into a modern country, where they are instead motivated to make a career of writing more efficient digital advertising systems or spend most of their time applying for grants and justifying the commercial potential of their research
(notably, I'm not arguing that "the easy parts of science are done, and thus, it takes more effort for further progress"; it may be true, but that line of reasoning alone can still justify the "moar [sic] population!" argument)
but, "fixing systems" is hard, just throw more people at it!
I guess what I'm trying to really get at is that there are multiple levers to progress
(let's not even open the can of worms that is "what is progress? who gets to decide?")
maybe those ad optimizations are Einstein level progress
...and population growth tends to exacerbate systemic issues (due to population pressures)
...and implying that we probably have more geniuses-per-capita than ever before (ex. Flynn effect) but a less effective system (than, say, 100 years ago) for them to contribute
anti-great-man-thinking suggests we shouldn't be looking for individuals anymore, and looking to the system for progress
I just don't see absolute number of "geniuses" as being the thing to optimize (because "moar population!" does not change the relative number, and may be causing problems faster than solving - yes, we're inventing new things, but quality of life isn't always improving for everyone)
(this whole subject is messy: who is a "genius"? what is progress? what is valuable? who gets to decide?)