Comment by eyelidlessness

The point of a type system isn’t ever that you don’t have to check the things that make a value represent the type you intend to assign it. The point is to encode precisely the things that you need to be true for that assignment to succeed correctly. If everything is in fact modeled as an Option, then yes you have to check each thing for Some before accessing its value.

The type is a way to communicate (to the compiler, to other devs, to future you) that those are the expected invariants.

The check for invariants is trivial as you say. The value of types is in expressing what those invariants are in the first place.