The "American Dream" as coined by James Truslow never existed: "a dream of a social order in which each man Sand each woman shall be able to attain to the fullest stature of which they are innately capable". So, I guess my answer is NO. Is everyone "able" to attain the fullest stature of which they are innately capable? Well "able" means "to have the power, skill, means, or opportunity to do something". I guess there is a greater than zero chance of it happening for everyone, but the power and and opportunity part of that definition is becoming less likely by the day. I'm almost 50 and I recognize that it is near impossible for the kids today to have the same things that the boomers (spit) did. Possible? Sure. As easy as it was even 50 years ago, no f'ing way.
I hear this, and then I see a lot of people in their 20s who came from poor or middle class families yet they're making six figures. Some are millionaires, e.g., Nick Huber (Google him).
Yeah, it takes some brains, but it really takes some ambition, initiative, willing to risk failure (but what are you really risking in your 20s?), a little discipline, and a work ethic.
Everyone IS able to attain the fullest stature of what they're innately capable; most people (myself included) don't do it. Why? Because we get comfortable. I've made a ton of money, lost it, made more, lost some of it... my problem is that I'm not risk-adverse enough. But even I am learning! And there's plenty of opportunity, but you have to look for it, and then you have to recognize it.
Any young person can become well off by the time they're 30 with a simple recipe. Learn a trade by working for someone else... construction, plumbing, electrician, garage door repair, landscaping... service jobs that cannot be outsourced to China and can't be replaced by AI. Save your money, buy the tools you'll need to go out on your own. Once you've put 3 to 5 years in, you should have learned enough to go out on your own. Put out your own shingle. Build relationships with customers and fellow service workers in adjacent fields... plumbers know electricians who know contractors who know roofers who know, etc. Use those relationships to send work to others and to get referrals from others. Start an LLC, get a logo put on your work truck, have a separate phone # (you can support two phone numbers on one cell phone today, or use Google Voice). Get a website. If you can't make in the upper 5 figures in your mid to late 20s using this approach you're not trying. Yes, you may have to move to somewhere that has enough demand; you won't make this living in a town of 2,000 people.
Or, go to college. Get a degree in tech or go into medicine: computer science, mechanical engineering, electronic engineering, aerospace engineering... nursing, pre-med, PT, etc. Yes, that will cost more. You'll make it back IF you study hard, apply yourself, make good grades. If you leave college with a 2.5 GPA you'll be lucky if you can get a shift manager job at McDonald's. If you leave with a GPA of 3.5 or above, you'll have a lot of job offers. Why? Your GPA is directly connected to how hard you work and how much you persevere. It will take hard work for 3 to 5 years to pay off your loans, but you can do it, and then it's off to the races income-wise.
A decent job in your 20s sets you up for success. Buy a duplex, live in one side, rent the other. Eventually, buy another duplex, rent both sides. Rinse and repeat.
The point is, there's LOTS of ways to become wealthy (not super-rich... some of that is luck), but becoming a millionaire can be done in a decade from scratch, with hard work that is smartly directed.
If you don't think the American Dream exists, that's the problem. Look at what you do, what you spend money on, how much you save... maybe it's not the lack of the American Dream, it's the lack of the right moves on your part. The good news is, every day is a chance to re-invent your life. Ray Kroc started McDonald's when he was 60 after decades of a mediocre (at best) career in sales.