Aside from where you said about making any worthwhile money here at 18, holy hell are you right about everything else. I used to be
much more career oriented, and put a lot of my focus on a highly job-centric life. But from college, to one job, to the next, it was just one big disappointment after the other. I really felt like I was never going to be satisfied with my life for some reason. I was pissing away so much money on things like degrees and certificates and licenses and with each one I was even less motivated to look for something else.
Then, one day a huge sack of bricks burst through my window and smacked me in the side of the head so

hard I was out for three days. When I finally came to, I realized I had it all wrong the whole time. Why the hell would I want my life to revolve around something as arbitrary as a job? Maybe that works for a lot of people, but I sure as sh* am not one of them.
I realized a job was only that. A job; nothing more than a means to fund an actual life that begins again as soon as you punch out. They all suck. And you can jump from job to job for years, fighting for "promotions" and "climbing the ladder", trying to be happy with your silly "career", but all you really can hope for is to find the one that sucks less.
Once I got into UPS and started driving, I eventually realized that this is probably the best possible spot I could be in. A high hourly-waged job where you only work from punch to punch with positively no personal involvement while off the clock. Now, people who say they love what they do, they're full of it. But here, I at least like it
enough that I really see no point in looking elsewhere. It's not
easy by any means, but it's
simple.
Some days suck pretty bad but that's any job. And the days that are good (or at least decent) fly by so fast you're making your last pick up and driving home before you know it. And it's true you'd be hard pressed to find a comparatively compensating, more secure job that allows you to keep your nose so clean.
From what I can tell about your attitude towards jobs I think it will be a decision you'll be glad you made. Maybe get a CDL or something as a safety net, but other than that, just ride out the game like I do and enjoy your life.