Yes, results aren't equal among the population. Those that focus on what they have rather than what someone else has tend to do better.
I go to a climbing gym several times a week. When people first start climbing, they aren't sure if they are cut out for it. Maybe they are too old, the wrong sex

, weigh too much, not strong enough, etc.
Those are excuses even though there may be a grain of truth in some of that. However if you point out that they can look around the gym and find someone else in their "category" that does climb a lot better than them, they quit complaining and then they get better.
Undoubtedly, there are plenty of people who are irresponsible--or just plain "bad" *--with money, but they by no means account for the vast majority. You seem to be buying into something akin to the myth of the "welfare queen." Simply put, the vast majority of households in the U.S. do not make enough money and/or have far too much debt to set aside much of anything for savings. This also inhibits them from furthering their education, and accruing even
more debt, and getting a better paying job. And then, some sort of emergency or dire situation comes along, setting them back even further.
As noted in another thread, neither of us personally come from a stable economic background, yet we managed to get out of that. Doesn't mean
everyone can. Also, I'm a white male--that alone afforded me considerable privilege.
* . I suspect that you are somewhat like me in certain respects: I tend to regard an awful lot of capabilities as just plain "common sensical," which, upon reflection, clearly
are not. Managing money sensibly is quite a skill--one that I, fortunately (and of necessity), acquired quite early in life. When I said that we both "(got) out of that" above, I didn't mean to imply that I've attained what most would describe as "comfortable" financial security; rather, I simply know how to live, erm, "comfortably" without working all that much or earning all that much--epilepsy is somewhat limiting, but also, quite frankly, I'm kind of lazy and I prefer "play" (music, dogs, hiking, biking, etc.) to "work" (see Bob Black). Of course, I also can make money from my "play," but it's never been all that much because my "play" is simply too weird.