Those that don’t have the discipline to teach themselves probably are among those who don’t even belong in college. They need a large dosage of ditch-digging to properly motivate a desire to learn.
There are those that have or can summon up the discipline. I would argue that many uneducated jobholders can better themselves by working for a degree on line while holding a real job.
I have in mind a specific person. He was twenty something. He was a forklift driver. He realized he needed education to advance. He had a wife and at least one kid. I lost track of him but suspect he would be a prime candidate for online education