Then, let look at these three places as simple studies.

1. Turkey - cats have been roaming free on the road. It’s part of Cat’s Right (Signatory of Istanbul Convention) for them to run freely. By now, birds should be extinct there by OPs logic.
2. Those people living in poor area in Mumbai - They’ve been living in the slump areas all their life do you think they care about environment and birds dying? They even struggle to think how to live the next day. They don’t care and won’t change at least until that place turn middle-class.
3. My place somewhere in South East Asia - On average, every house will open its windows and doors early in the morning until the evening, especially in the village area - part of the culture/belief to bring wealth (rizq - google that) in. By logic, the reason is to keep the house cool. I bet you don’t know this even though you said you travel a lot. May be you need to stay instead of just travelling so you pick up people’s culture better. Anyway, back to it, mostly the posh have cats indoor because usually they have special breed, e.g. Farsi. Good luck to keep cats in when the doors and windows are always open.

That’s only three places. You go to different places, they have their own niche issues. Until they can solve their problems or change their culture, they can’t simply change just because you tell them what they’re doing are bad for the environment.