If Thanos had, instead of randomly wiping out 50% of all living things, he had instead in each species wiped out only the dumbest 50% what would the reaction of each avenger have been?
I think the whole 50% depopulation is a flawed premise, of the hundred of thousands of years modern humans have existed that would throw total population back to... 1970
Yup. His movie motivation was dumbed down. The whole resources thing is stupid for exactly this reason.
In the comics, Thanos became infatuated with the Marvel Universe incarnation of Death. ...And naturally he figured that if he killed half the universe at once, he'd get her attention. (cause girls love it when a boy makes a huge amount of work for them...)
Anyway, his plan was still moronic, but "manchild does stupid thing to impress girl" is a classic for a reason.
It wasn't just humans, it was the whole universe. He wasn't concerned with how each individual species' populations would fluctuate, he just had a solution in his head and went with it.
There is an addendum to his plan that might have made it make sense. If he had said something like "I'm giving the universe the chance to make better decisions", suddenly having half as many people means (probably a little more than) half resource consumption, half the carbon emission, and more time to figure out and implement solutions to these problems. I'm not sure how the housing crisis would pan out, I expect it would get worse. It also makes more sense that he destroys the stones after "I gave the universe its chance, now the ball is in its court".
This also solves the doubling resource problem. His motives are to pressure people to change their ways. Giving them more stuff might cut hunger, but you'll just have that hunger again in 50 years and we'd probably increase carbon output to boot, and destroy more environment to get these doubled resources.
I don't know enough about the stones to say whether "infinite resources" or whatever cheat code would have worked, but they certainly could have dropped a line that it wasn't possible, or that it would cause more problems than it solved (how does chemistry even work in this universe? If nothing ever gets used in reactions then the chemistry that makes our bodies work is borked)
But anyway, as the Russos did not put this line in, the premise was flawed