Leaning heavily into object orientation, including baking in things like companion objects, object expressions, etc. Encouraging utility classes that tack half-baked functionality onto existing types. Smart casts encouraging overly complex hierarchy.
While operator overloading and infix functions aren't a Java anti-pattern, I also think the language would be improved by their removal.
Even if you sincerely believe that OOP is an anti-pattern, surely it was firmly "baked into the language" in Java already? Kotlin is fundamentally a better Java, not a rebuttal to Java.
It is all but impossible to use Kotlin without an IDE telling you everything, and for that I find the language interesting. And for comparison, I did in fact write Java without an IDE for an extended period of time.
