On the other hand, people who have grown up in poverty have been conditioned to believe that excellence doesn't really matter since there are few or no rewards to be had. Keep in mind, this is well below the level of conscious thought - it's a biological response.

Once you remember that humans are animals and are conditioned by their environment the same way animals are, stimulus and response, everything about our modern civilization makes total sense.

Now, in some respect everyone has the same amount of agency. No matter how rich or how poor one may be, they can tell the world to buzz off and do whatever they want to do, so in that sense they have the same agency. In reality, most people have an impulse to survive and meet those needs, like having food and so on, and people are cognizant of this fact. So unless you have the ability to provide all your needs, agency is mostly an illusion. Sure, you can do whatever you want but it’s a lot easier if you have a pile of money to cover your whims. If you don’t, well you might starve to death or die from some easily curable disease.

I know this is pretty obvious and may not entirely answer your question, but many people find it very difficult to swallow this reality these days and I think it's worth reminding.