I was mainly arguing against golang. As for Kotlin, given the incredible work that has been done in Java recently, the argument is that there isn't much reason to switch over anymore, due the introduction of more moving parts into the project (another dependency, compiler, room for issues, etc.) and the fact that Java ended up with the superior approach (better/fully fledged pattern matching, virtual threads, programmable string templates, etc.).
And I've worked with programmers who use the latest fad of the day (golang, etc) and they're not the ones you want to have on your projects.
> The best talent don't even want to consider working with Java if they can help it.
Not in my experience.