I mean having a monadic api is nice if it's strictly enforced by both ecosystem/culture/typesystem. But with Optional being potentially a null itself, it barely

I mean having a monadic api is nice if it's strictly enforced by both ecosystem/culture/typesystem. But with Optional being potentially a null itself, it barely improves the need to defensively program and might in fact be worse. For example, when I used a lot of Scala in a past job, Java libraries were scary to use unless you defensively wrap java functions with Try/Option/etc. Whereas with Haskell/Rust/OCaml/etc. you can largely trust type signatures to properly encode the existence of nullability or failure.