Even optionals with bad 'is null / get' assessors are better than nulls, because they come with nullsafe operators like map / flatMap and the 'get' call usually always errors or panics on failure.
The important part is moving `null` out of every type in the language, and into its own little box that the compiler can tell you about. It's nice if you can make it a "library" utility without holes, but it's also fine if it's not perfect, or even if you have to make it a builtin magic thing, like C# &co.
> flatMap or Map must call the has_value method to work without crashing.
The implementation details don't really matter to the caller, what matters is that they're always operating in a safe environment without being bothered.
It matters because it's not true safety. flatMap is a higher level operation, I can make >=> or >>= work for values with null but that's not true safety.
True safety as you said, is no null. But an optional that still generates a runtime error is basically isomorphic to a null. The point of getting rid of null is not null itself, but the associated runtime error that comes with it.