One good thing that came from Kotlin, Rust, or even Javascript is, data structure is very cheap. You can declare a type and instantiate it in a bliss.
What differ between data-first and object-first is come from the fact that we always try to hide data in an object and expose supposedly safer “methods” to manipulate state. When you have object instead of data, you are encouraged to create actions and not direct data manipulation. This action-based is fine by itself, but really cumbersome when you need to handle varied data that has little pattern or similarity.