Does Kotlin have the maybe monad?
Not in the standard library. Kotlin went with specific language features to achieve null safety:
https://kotlinlang.org/docs/reference/null-safety.html
Personally, being able to solve problems with the abstractions you can achieve within the language over adding very specific language features to solve them appeals to me more.
Having said that, Arrow has Option: https://arrow-kt.io/docs/apidocs/arrow-core-data/arrow.core/...
Isn't Scala minus the problems you mentioned just Kotlin?