I think that is another great aspect.

Doing a "gap year" and deciding later if I wan't to visit college.

Given the market and his skills, college will never come. He’ll just get into and immersed in the industry and forget about College. The idea of college will only hit later.

Realistically, however, college is only important if you are planning to leave your own country; or get involved in a very bureaucratic/hierarchical company. Since he is from Germany (which has a quite powerful passport), college will only be important if he wants to immigrate later to the US.

Another way that a degree becomes useful later on is once you need to write a bio for your photo on your startup's About Us page. The vast majority of bios, even for old wealthy folks, list the degree and university in the first sentence.

The "college experience", however, won't be available anymore when you're no longer of a similar age as your peers there. I wouldn't have wanted to miss out on that.

Lots of people start college 2-3 years after finishing high school. That age difference is no big deal. I think many people actually benefit from taking a year or two away from school before jumping in for another 3-5 years.

Yeah I'm explicitly not saying time off in general is a bad idea, but it'd be a shame to wait too long/never do it.