For reading it, I believe that. For authoring it, yikes it is slow. I'd guess due to all the implicit and implied and coercion and ... and ... and. Now I'm cognizant that I'm running my mouth without trying it on 1.9.x and a similarly recent IJ so maybe it got infinitely better, but my life experience with languages is that they only get more fancy swooshings not QoL improvements due to Moore's Law and yearly refresh cycles

I was/am always glad to pay that tax because non-null-by-default and the vastly superior val/var keyword pairs are totally worth it but it for sure is not a drop-in replacement in team environments. I am already constantly battling the vscoders (to say nothing of vimers) whining that "IJ is too slow for my eeee-leeeet typin'"

Definitely also for writing it.

Looking forward to JetBrains proposal to rewrite Java Virtual Machine into Kotlin Virtual Machine, certainly the existing Java codebase would be largely improved.