The point isn't to make a system that is easy. The point is to make a system that is guaranteed to work in any remotely realistic circumstance.

In a real black start, the guys might very well grab a portable generator and just use that instead. But having the option to hand crank something rather than rely on batteries that might run flat is good.

and if the entire thing depends on it, you'll give that generator a handcrank as a backup too instead of assuming the batteries ever dying or getting flooded or whatever is entirely impossible.