Kotlin makes a lot of that stuff easier to deal with and there is also a growing number of things that work without Java libraries. Or even the JVM. I use it with Spring Boot. But we also have a lot of kotlin-js code running in a browser. And I use quite a few multiplatform libraries for Kotlin that work pretty much anywhere. I've even written a few myself. It's pretty easy to write portable code in Kotlin these days.

For example ktor works on the JVM but you can also build native applications with it. And I use ktor client in the browser. When running in the browser it uses the browser fetch API. When running on the jvm you can configure it to use any of a wide range of Java http clients. On native it uses curl.