I feel like the "don't get hooked on drugs, graduate high school, and don't get pregnant or get your SO preg before 25" is just stating that by doing some basic table stakes things, you exponentially increase your odds of succeeding to being above the poverty line and being self-sufficient and not dependent on the government for day to day survival.
Just like being born an American doesn't mean life will be perfect, by being born an American in the richest nation where like a $40k annual income puts you in the top 10% of the world, you have a better chance at not being abjectly poor. I think I read the average American income is like $45k these days (shoutout to Wharton grads), but I think that's the big idea:
It's not a playbook that guarantees any success and it's not a blueprint to happiness, just a way to minimize risk and assure at least mediocrity.
That said, sure there are pockets of American society where populations and cultures are horrible and not getting pregnant and not getting hooked on drugs and graduating high school might be a huge thing, but generally speaking it's not a heavy lift for most Americans.