Why are collections truncated in Kotlin?

Question

Kotlin

There are really many standard collections in Java for any occasion.

But why are there so few of them in Kotlin?

With what it can be connected?

Answer 1

The answer is multiplatform.
When writing Kotlin under the JVM, you can use the entire set of Java collections. The picture below is somehow incomplete, at least there is no Map and MutableMap on it. As a maximum, since their java.util.HashSet implements MutableSet, then LinkedHashSet, TreeSet too.
But in general, this is not fair if the code is compiled under JS or Native.