This is of course ignoring quality issues....
Plus... if Kotlin really is the new hotness and companies want it then mediocre devs can also learn it.
So any "genius early adopter" advantage that Kotlin might have is short lived.
Though speaking from personal experience, the dude/lady with 5 years of java 7 and below experiences gets stuck in their ways and doesnt write more modern Java code. I had one dude who got mad and would try to block PRs if you did lambda functions from those bodyshops.
My experience dealing with body shops. If you ask for Kotlin, the body shops will send you devs that have Kotlin on their resume, and if your lucky the body shop had them do a 10 hour online course on it. If your corporate model uses body shops you are probably gonna get better results from them with a more mature language than something newer.
As for quality, the app worked and works well, but there were some serious WTF design decisions made that have made it impossible to maintain the app, not to mention total lack of testing.