The human race really cannot be trusted, we would just reproduce back to billions of people again. Everyone thinks they are something special and worthy of reproduction. Our intelligence has eliminated any impediment to allowing everyone to genetically litter the world with humans that we don't have room or resources for.
If you study how terribly we have devastated the ecosystem, and if you value the ecosystem in a relatively benign way, the solution is clear and it does not involve a human species. We are too selfish to want to admit that we are devastating the planet, so people go into total denial of ecological devastation like they do a total denial of covid-19.
For almost every terrible truth, there is a way for the human mind to buckle to keep its beautiful subjective world in tact. Some people crack along the way. A lot of people stay in denial.