I prefer Java in VS Code, but unfortunately there's no solid option for Kotlin outside of IntelliJ.
One of my two major gripes about Kotlin -- that, and the lack of a standardized style guide and formatting tool so that there's no bikeshedding or difference between repos.
Visual Studio is still the best for C++, followed by C++ Builder.
VSCode is the only Electon app that I tolerate on my own computers.
When is InteliJ finally going to support JNI development instead of requiring two IDE licences?