Why are NYC, Boston and Chicago ignoring the obvious solution to rats?

I just got back from Istanbul, and it’s honestly embarrassing for those cities. Istanbul is more crowded and chaotic than Boston, NYC, or Chicago, yet I didn't see a single rat. Why? The cats! In the US, we spend millions on "Rat Czars" and poison that just ends up killing hawks and pets. Meanwhile, Istanbul has a literal army of street cats keeping the rodent population at zero. I don't know if I'm missing something but seemed like basic math: more cats = fewer rats. What do you think? It seemed like Istanbul is rat-free because they respect their cats meanwhile NYC (or other major cities honestly) is a dumpster fire because we think we can outsmart nature with bureaucracy.