In the comics, what he does has nothing to do with resources or overpopulation, he actually kills half the universe because he's in love with death (which exists as a female character in the marvel universe) and he wants to impress her.
The explanation that I heard about why he doesn't just make more resources is because the stones aren't that powerful in the MCU, killing 50% of all life is much easier than literally duplicating every single resource in existence, and even an easier task like killing people almost breaks the gauntlet (you can see it's crushed and smoking after he snaps his fingers), so duplicating everything would be impossible. Another explanation that I've read was that the stones can control what's already there (the finite matter and energy in the universe) but are unable to make more of it. However yeah I do agree that his plan is ultimately very stupid like I explained back in #30
SentinelAlso, thanos' plan is dumb altogether, destroying 50% of all life indiscriminately at a random point in time is meaningless since populations grow so they would go back to their old numbers in a few generations. We can also see that the gauntlet gets pretty much destroyed in the process and he crippled the only blacksmith that could make it, so he can't exactly repeat the process every once in a while. Not to mention that destroying 50% of all life indiscriminately means you kill 1/2 of the population even on planets that have absolutely no issue with overpopulation and even planets with dwindling populations. At the end of the day whatever nerdy explanation people come up with to patch the various plot holes is fairly irrelevant, the bottom line is what happened happened because disney thought that particular plot would optimize profits from the movie.