I'm not an anti-natalist or anything of the sort, but it would appear to me that if anything, the evolutionary challenge facing humans is that we have had too many babies. Across the globe we've consistently created more humans than our ecosystem can reliably support, or that we can manage to support with our technology.

This has resulted in climate change and ecological destruction.

A future earth with the highest carrying capacity for life might look like the entire globe as rich in life as the Amazon rain forest, with humans benefiting from the enormous diversity. Our ecological niche would be in the microbiome, where the human species eliminates diseases, causes maximally high survival rates in other species, and uses this surplus for our energy supply, along with genetic engineering species to suit our needs.

FWIW, I think many are concerned about conservation already, which I think is the key to our long-term survival as a species.

Not so much of an issue as long as the population keeps increasing (maybe even the opposite...)