Even if you believe the debunked overpopulation stuff: We're below replacement levels here; we're not the problem if there was one.
That's because even with for place near the top of almost every measure of good places to live, you're still cold and dark for half the year. Elsewhere, people are cranking out kids at up to 3 times replacement level.
We'll probably reach a balance worldwide sometime in the next couple decades. Currently it's about 20 births/1000 population and 8 deaths/ 1000 population for the world, still double replacement level.
The real problem is there will be lots of old people around and cluttering up space until they finally die off. Western nation will clear out the deadwood (pun slightly intended) in about 30 years, and China in 50 thanks to their one child policy, but many countries won't get over their bubbles for 60-80 years depending on when their peak was.
But to directly address your beliefs, overpopulation is hardly debunked, there are just lots of variables, some of them unknown and some of them estimates, and different estimates naturally give different results. Overpopulation is a matter of how many resources each person uses, not how many people there are, ultimately. It's simply not possible on water resources level for everyone to live like Americans, or even Swedes, in the places everyone is now, for example.