A lot of great minds I have studied with simply shrug when asked what they want to do for a career. Hence Google has its pick.
Admittedly, many people know damn well what we like doing, but are just about equally sure there aren't any actual jobs doing it.
For example, I like academia. It's not perfect, and I could certainly make some improvements (like more money, less bureaucracy, less enforced hierarchy, and more personalization of... everything), but next to business life (at both a mid-sized corporate environment and a niche bespoke software business), I like it and I'm good at it. That doesn't mean there are anywhere near as many jobs available for aspiring academics as there are qualified aspiring academics.
Admittedly, many people know damn well what we like doing, but are just about equally sure there aren't any actual jobs doing it.
For example, I like academia. It's not perfect, and I could certainly make some improvements (like more money, less bureaucracy, less enforced hierarchy, and more personalization of... everything), but next to business life (at both a mid-sized corporate environment and a niche bespoke software business), I like it and I'm good at it. That doesn't mean there are anywhere near as many jobs available for aspiring academics as there are qualified aspiring academics.
Eventually, something has to give.