I've met many people from poor backgrounds who turned into multi-millionaires, including numerous immigrants who came to the US literally with $0 and unable to speak English. Our family lived below the poverty level for many years before climbing into the middle-class and eventually upper-middle class.
The only thing keeping poor people from succeeding is their sh---y attitude. Poverty is an excuse that losers use; winners don't make excuses. Each one of those successful people I knew had plenty of excuses to fail if they chose the failure path.
Do me a favor and indulge in a short thought experiment with me. Imagine a kid, one of the hard working driven kids, who grows up in McDowell County, WV. Dad dies of a heroin overdose, mom's an addict, a couple siblings you're de-facto raising, one of whom is frequently in serious trouble. You spend 7 hours a day at your barely functioning high school, then spend another 8 hours at your minimum wage job providing for your family, all the while living under stress levels beyond what you and I see in a lifetime. Between the school quality, time constraints, and sleep deprivation you don't have anything beyond the most basic of education, and you didn't win the genetic lottery for IQ so learning is harder for you to start with. You didn't get to play sports, read any books, browse the internet, teach yourself to code, collect comic books... or engage in intellectual curiosity of any kind. While you speak English, you've got an accent that the rest of the country marks you as ignorant as opposed to someone with, say, an Indian accent.
How does that compare to your high school experience? I would consider myself the epitome of laziness compared to him, and I'd guess you would have to as well if you were being honest. And yet here I am, all proud of myself from going from lower middle class to 1 percenter because I don't have a shitty attitude like him. Yes, a couple people from McDowell County are going to go from grindingly poor to success, just like a few of the most driven people from India are going to immigrate to the U.S. and be successful against high odds. That kid might be one of them, but he'll have to have far more luck and work 100 times harder than you or I ever did. That in no way means the rest of the desperately poor people in McDowell County or India are only poor because of a shitty attitude. The fact that anyone could think that is in and of itself about the shittiest attitude I can imagine.
I came from a lower middle class background, and it sound like you did as well. We have NO FUCKING CLUE what it's like to grow up grindingly poor surrounded by grinding poverty, addiction, and hopelessness. The people who succeed coming from that are exceptional, and you and I most probably are not. I'd highly encourage you to spend some time volunteering to work with kids in a place like this. After 6 months, let me know if you still feel that "The only thing keeping poor people from succeeding is their sh---y attitude." Until then, have a little humility and at least try to walk a mile in another man's shoes.