Using `Either` instead of `Option` would violate "Use the least complex approach that solves your problem".

If all you need is represent an optional value, why use `Either`, which needs a second type parameter representing the failure? If you don't care about what caused the failure (because there was no failure, an absence of value is a valid result), no need to represent it.

Besides, these two classes still represent fundamentally different concepts and they are not interchangeable at all.