I daresay the experience of hustling and trying to build a company is a valuable form of education even for the 80 who fail
So for many people, acquiring signals is a complete waste of time and money.
I suspect that for the latter ones (how many? maybe 20-30) that wouldn't even be educative at all.
18 year olds are idiots (source: was one) and are simply not capable of managing organizations of adult humans.