The premise of your question is inaccurate
("...Scala Akka does not."). From the akka documentation:
Actors give you:
Simple and high-level abstractions for concurrency and parallelism.
Asynchronous, non-blocking and highly performant event-driven
programming model. Very lightweight event-driven processes (several
million actors per GB of heap memory).
A basic example of asynchronous message passing to an Actor:
val actorSystem = ActorSystem()
val actorRef = actorSystem actorOf Props[SomeActor]
val message = ??? //some message value
actorRef ! message //asynchronous message passing
In fact, akka exceeds the original Actor Model specification with the ability to lookup Actors by name.
For IO specifically, akka offers many non-blocking solutions:
Granted, Scala the language does not have an embedded Actor Model. But it provides Futures and parallel collections for concurrent computation.
The gist of the blog you quoted was that Futures are much better for concurrent computation (which I agree with), while Actors are for maintaining state. It wasn't claiming that Actors are incapable of concurrency.
Plus, akka is not just Actors. There are Agents, finite state machines, akka streams (implementing the reactive manifesto), and the akka-http library.