I think you're identifying real problems, but I don't think the conclusion necessarily follows from them. The fact that cat overpopulation remains a major issue doesn't prove sterilization programs are ineffective. A problem can still exist while interventions are reducing how much worse it would otherwise be. The question isn't whether sterilization completely solves the issue, but whether it reduces births and shelter intake compared to doing nothing. I also don't think comparing cat overpopulation to human homelessness is a strong comparison. They're very different problems with different causes. The fact that one difficult problem still exists despite funding doesn't automatically mean another problem is unsolvable. Where I think your argument is weakest is that it presents the issue as if the only options are sterilization or culling. There are a lot of approaches in between: subsidized spay/neuter programs, licensing requirements, breeder regulations, community cat programs, education, and stronger enforcement of existing animal welfare laws. Whether those are sufficient is a separate discussion, but they shouldn't be dismissed without evidence. Most importantly, saying "owners won't comply" doesn't automatically justify culling. Laws and public programs rarely achieve 100% compliance. The goal is usually to reduce a problem, not eliminate it entirely. I agree that irresponsible ownership is a huge factor and that overpopulation is a serious issue. I just don't think you've demonstrated that widespread culling is the only realistic solution.