Hmm, I been on a total of 2 kotlin projects, both went badly.

On the other hand, we have several hundred java projects, with a very low project failure rate.

Maybe java is missing some things that are trendy and you get used to using, the things we missed most in kotlin was working code that was easy to debug, repurpose and deploy.... Stupid issues like the compiler not working properly or just taking ages burnt to much developer time, and to hard to find staff to make it up.

But heh, maybe I'm old fashioned, it doesn't seem like a popular opinion. But nothing in this thought piece seems to address those fundamental issues.