This also has significant impact for serialization/de serialization - a classic place where you get unexpected nulls, that Java Optional/Maybe don't help with at all.
Types are both for the compiler, as well as for the developer. Maybe types are implicit documentation telling the developer that it is meaningful in the application that this field can have a None state.
That's a huge code smell to ever set null to an Optional/Maybe and code reviews, linters, nullness analyzers all should/will flag such.
Like I have never ever had an NPE from an Optional being null. Sure, complete null safety would be better of course, but in this very instance it ain't buying you much.
Use a regular class to signal that you may or may not have a value.
Wrap it in an optional to signal that you may or may not have a value.
See the problem?
Well wasn't that the argument above, that the stuff they added so far isn't proper at least in part because they didn't fix that problem yet?
And a promise to eventually fix a busted implementation doesn't undo it being busted for a significant amount of time.