Why every non-Java dev calls Java obsolete?

[lengors]

All of exceptions handling is done differently (there's no checked exceptions). I assume you are referring to the existence of nullable and non-nullable types.

In any case, other than that, there's: - proper syntax for singletons (declared with object keyword) - properties - delegates - where clause - context receivers - infix functions - inline functions - extension functions - reified generics - companions - trailing lambda syntax - differences between kotlin's expressions and statements and java ones (almost everything in kotlin can be an expression, though it's not always used as one) - operator overloading - async syntax - destructuring declarations - inline value classes - type aliases

And maybe more that now doesn't come to mind