No, it’s not orthogonal. In Java, all reference types are implicitly optional. The explicit Optional type is only intended as a stop-gap in situations where the implicit version is especially error-prone. But in general it doesn’t make sense to have both the implicit and explicit solution, in particular when the explicit Optionals simultaneously also have the implicit optionality on top.

It’s exactly the presence of the implicit optionality that makes Optional nonviable as a general-purpose optionality mechanism (in addition to its performance implications).

But the language has another often-used idiom to express a missing value, null.

That’s why this was not intended for usage everywhere.