A modern programming language that makes developers happier.

kotlinlang

So to summarize: Arrow-kt brings the discrete concepts of Typeclasses, Abstraction, Reuse, Optics, and Fx.
These are the killer platform, and Kotlin is simply the happenstance of career-minded and popular imperative based language upon which to center the horizon.
Other languages do the killer platform tailored to their primary characteristics but Arrow is making a stand for Pure Functional? and settling in for Kotlin compiler augmentation to dampen the Kotlin glass ceilings starting with "Reuse", presumably to make a stronger case for reading clear code and model description.  "the alternative is learning" refers to dead ends in toolkit designs where they have painted themselves into a corner.