I once did a short gig with a start-up that used Kotlin and the CTO was very enthusiastic about Kotlin. He showed all the things you could do in the languages like adding behavior to an integer that would be applied throughout the program. He was excited and I was a little horrified haha. But huge companies have been built using Kotlin so who am I to judge?
I'm in the same boat as you, I want to solve problems and build products.