I hate to say this Drags, but the sad reality is that at current levels of resource consumption and waste product generation, there really are too many people on the planet.
Nnooope. Even if you kill off the bottom 80 percent of the population (bottom in terms of resource use) the resource usage wouldn't be impacted much at all.
[src] Which means that, since the effect on resource usage is not changed by such a population change, population doesn't actually have an effect on resource usage. Or if it does, it's a minor and probably negligible impact, considering you only cut it by 25% from a cull of 80% of humans.
It's not the population that's the problem, it's the overall distribution (some use way too much while others use barely any at all) and the usage of a small elite cohort at the top of the graph. "Trimming the population" would do nothing at best or make the problem bigger at worst, through various mechanisms. Not least of which is the remaining population (who, let's be honest, is gonna be the rich fucks. I.E. the ones using too many resources) are gonna go "Hey, more for us!" and then use EVEN MORE than they were before. Not to mention the impact of the actual culling mechanisms; you gotta kill 'em somehow. And even if you could Thanos them dead in a second, you'd still have problems just from the loss of people.
Not to mention that that bottom 80% of the population tends to live in Africa and Asia, and 'we have too much population!' has historically and continues now to be disguised systemic racism at best, out-and-out personal racism and hatred of the 'lesser races' at worst.
E:
If any of you have an hour to kill, this video goes into the history and current state of population, resource usage, and the historical and current state of the 'we have too much population!' argument. And yes, it's sourced, his sources are in the description and peppered through the video if you want to argue the facts he used.