Startups rely on Generalists who can specialize until the scaling happens, then it's about specialists who look to grow into generalizing/broadening.
Different skills needed for different stages of growth and not everyone can switch gears or have the range in transmission, founding leaders included.
Startups, and riskier technology ventures generally, seem to be the opposite. There you aren't Caesar, you're the Gauls. You're hoping that your team has just what it takes to overcome the odds.