> I'm terrified that I'm going to end up the same way.
First off - we don't know that guy's life situation. That is, what did he do after graduation? Or - maybe he was successful, and does delivery just to have something to do while he gains royalties on all his patents? Or maybe he enjoys physical work more than doing chemistry at some company? Or maybe he was employed, then convicted of some crime he was a part of with an employer? Tons of possibilities, we (and probably you) just don't know what led him from there to here.
There's no way to know if this is how you'll end up; but your first question should be why you feel you may end up the same way?
What is it about your current situation (employment, life, etc) that may cause you to "fall down the ladder"? If you can answer that, then you'll have at least a clue as to what to do or try to prevent it.
I'll use my current situation as an example (maybe even a warning?):
I'm a software engineer - big whoop, right? So are a lot of people.
I'm also 45 years old. I've been a professional SE since I was 19. Unfortunately, I didn't do everything I probably should have done, and now I am making up for "lost time".
Biggest mistake: Not saving my money early. In fact, it took me a long while to learn to save money - and also to get off the credit spending cycle. Fortunately for me, I broke out of it - and today I am "debt free" (I call it "Dave Ramsey Debt Free" because I still have a mortgage - but that is secured debt, so it doesn't really count). I have a lot of savings - not as much as I could have had, but more than the average American does.
That gives me some flexibility - mainly in my career. I have what could be termed "FU" savings. Basically, I can tell my employer to "take a hike" if I want, and still be able to live comfortably for a while until I can find another job (not that I want to - I like where I'm at right now).
One thing I have done over the years to insulate myself from being unemployed has been two-part: I keep my skills up-to-date and varied (everyone should do this), but I also, in the field of being an SE, keep my skills general enough that I can apply my knowledge to get up to speed on whatever it is that my employer may need or want me to do.
I don't focus on the skill or language "du jour" so-to-speak. Chasing that demon will only lead to fruitless heartache, if not a lot of stress. Instead, I seek to improve my skills in more general avenues that can be applied more narrowly to situations.
To that end, in recent years I've been pursuing using online resources - learning what I can about ML/AI; I've yet to use what I've learned at an employer (these new skills have included a focus on self-driving vehicle technology - but there's a lot of general skills even in that which could be applied more broadly, which is the takeaway I seek when I pursue self education opportunities) - but I believe that having them may help me to find future employment if necessary.
That said, I do worry about hitting some kind of an "age ceiling" given my current age; one area that I've never had an opportunity to try has been that of "management" - I've never been a team lead, or a manager of a team, or anything like that. I don't know how to gain that experience except by doing it, but if you are never given the chance to do it, you never gain it. Furthermore, I am not sure I would be good at it - but I've never been tasked with it. I worry that this lack of management experience may hinder me going forward as I get older.
But I have no choice here, except to keep doing what I have been doing that's been successful for me.
That's about all you can do yourself - try to find a career you can enjoy going to every day, make yourself relevant to the business needs, continue your education, especially towards more general knowledge in the problem domain that can be adapted more narrowly if needed, and in the meantime, increase your savings and reduce your unsecured debt load (ideally to zero).
I can't speak toward investment or anything like that - those are other skills and such that I lack, and I don't know how to gain them. I'm not even sure at this late date if such knowledge would matter. But if you are young, you might look into such a thing, whatever "investment" means for you.
There's no guarantee that any of this will prevent you from becoming a "service worker" - or someone with an advanced degree working for a pittance. All you can do is to do what you can to prevent it, and know that may not be enough in the end. But it may be enough to slow things down during the "fall" - should that happen - that you can pick yourself up and figure something else out to reverse your fortunes.
Oh - one other thing I forgot: I don't have kids - that was a decision my wife and I made a long time ago. Not having kids helps greatly with savings and debt-load issues. But that's another choice to make; everyone is different in regards to whether to have children or not, just realize that they can be both a "burden" and a "blessing" - and to plan accordingly, for before and after should you decide to raise some.