I mostly agree with you. Maybe our emphasis is different. I try to look at the issue from a practical standpoint. I can't change where I was born or how much money my parents had or even what I did 5 minutes ago. What I can do is take my present set of circumstances and do what I can do to make things better from this point on. If I lay in bed all day, things aren't going to improve but if I get on this computer and work until 9 o'clock tonight doing what it is that I do then I stand a pretty good chance of having a more prosperous future. Especially if I do that consistently. And it's hard work. I'd rather play video games but I don't. I work.
Regarding the people you grew up with, you say they work as hard as you do. Are you sure about that? And while they may be working hard, how smart are they working? For instance, some went to college, did they get a degree in something that is in high demand where the pay is good? And getting a college degree is only one piece of a good education. How much did they really learn, and consequently, how competitive are they in the job market? Even if they're all in high demand STEM fields, they still have to compete with the thousands of other job seekers after all.
Thinking through the alternatives and making smarter choices is hard work. And that is cumulative. It's kind of like compound interest too. You may not see a big difference from day to day or month to month but given some roll of the dice in circumstances, over the course of years and decades, working hard will almost always make a huge difference.