Is overcrowding the root of (many of) humanities problems?

I don't know if this is really a universal problem or just a symptom of my asocial outlook on life, but I think our evolutionary success has become the instrument of our impending downfall. Climate change, pollution, homelessness, the pandemic, famine, etc. are all exacerbated by population density.

"And you, be ye fruitful, and multiply; bring forth abundantly in the earth, and multiply therein." (Genesis 9:7) This was good advice when everyone else on the earth had just been drowned, and it's handy if you need a lot of spear fodder to fight wars, but I think we've reached the tipping point of abundant multiplication and are now experiencing diminishing returns. The world *as it is* is unsustainable.

Humans have always had a propensity for antisocial behavior and a small percentage of wackos becomes a large number of people when the population is high. Modern communication lets them band together and the rest becomes history (after appearing on the 6:00 News).

The Earth has become our prison and we probably won't get a pardon any time soon. Overcrowding has been studied on rats (see quote below) and in prisons. The prison study wasn't quite this horrific, humans have more behavioral options than rats, and cannibalism is severely frowned upon by most wardens.

"Unwanted social contact occurred with increasing frequency, leading to increased stress and aggression. Following the work of the physiologist, Hans Selye, it seemed that the adrenal system offered the standard binary solution: fight or flight. But in the sealed enclosure, flight was impossible. Violence quickly spiraled out of control. Cannibalism and infanticide followed. Males became hypersexual, pansexual and, an increasing proportion, homosexual. Calhoun called this vortex “a behavioral sink”. Their numbers fell into terminal decline and the population tailed off to extinction. At the experiments’ end, the only animals still alive had survived at an immense psychological cost: asexual and utterly withdrawn, they clustered in a vacant huddled mass."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2636191/

I regret to say that I don't have a solution. I will never have kids because I consider my genetics to be flawed, as evidenced by my overwhelming selfishness. Unfortunately, lots of other people who are as bad or far worse, apparently feel that their genes need to be expressed. I would like to see volunteer eugenics (not state sponsered), but it's never going to happen. Most of us are genetically and socially motivated to want children, no matter our genetic faults. Natural disasters, diseases, crop failures, and pollution; along with human ignorance, stupidity, aggression, greed, etc. are doing all they can to combat the problem, but we humans are hard to eradicate.