Just as wet streets don't cause rain, Oxford degrees don't make politicians. It's just that all the British trust fund kids go to Oxford to study .. well, whatever.
I always find it odd how the Cambridge educated prime ministers seemingly dried up, one would really expect it to be closer to a 50/50 split as it had been in the past.
College is a prerequisite for professional degrees. Hacker News crowd notwithstanding, your career earning potential is reduced if you only have a secondary education.
Note that not all college degrees are equal. Obviously. Four-ish years of dedicated study changes your mind appreciably, which is the real objective. Also, finishing a degree signals your ability to function in a somewhat opaque bureaucracy, which means you'll be able to follow dumb rules and still get stuff done in a business organization.