Besides being a very basic requirement, Having a good understanding of training principles doesn’t really matter. There’s a lot of people that can write theoretical, long-term progressive training programs that look good on paper.
At some point, for the vast majority of people, training by yourself- with no interaction with others- takes its toll after a few years. You don’t necessarily need a coach or a team I guess, but you likely need some form of social circle at some point in life-and having people that know a little bit about running in that circle makes it easier. In regards to not going to college, and training by yourself/coaching yourself, I think the biggest struggle you’ll face is in a few years...you don’t really have a great job, and shoes, gear, travel, and entry fees are adding up. You’re only running mediocre times (relative to national or world-class.. maybe you’re running 13:40/28:30 at 21 or 22.. still not going to get you anywhere even though that’s pretty solid).. At some point, it will just get old. It’s most likely you’ll face peaks and valleys with motivation. Sometimes you may not want to continue at all. Without any support, it’s just harder.
You don’t have to compete in college, but I’d at-least go to community college, take some classes, work a part-time job you somewhat enjoy. Make some running friends-even if you just do an easy run with them once every 2 weeks or something. Just have something in your life besides running, and some people in your life.
But to be completely honest, you mention ‘not having to deal with obstacles’. That’s just unrealistic. Whether you go to college or not, you will have obstacles. That’s life. I know good arguments can be made that the college system isn’t ideal for long-term development, but I’m just pointing out that not going to college isn’t going to be perfect and easy either. And even though there’s a few success stories of people “doing it on their own”, I’d guess the majority of people that skip college and try to run on their own stop being competitive after a few years. We all like to think we are the anomaly, and maybe we are, but you have consider what’s most probable as well.