I like the following article as a summary of what's going on in terms of why people don't focus on local altruism: Global economic inequality: what matters most for your living conditions is not who you are, but where you are. There's also this article from 2021: Don't we spend too much on foreign aid already?
People outside of EA generally emphasize local altruism way too much. This means that the most effective opportunities for helping people alive right now are very likely not local.
There's existing writing that addresses issues you've touched on:
And finally: EAs are into policy and systemic change. You should read more about that on the Forum: policy, improving institutions.