It's a Galapagos island full of stuff that evolved independently.

Concurrency is important, but if you are not familiar with concurrency primitives like mutexes, condition variables, barriers, semaphores, etc. and skipped directly to the actor model, that's a bit like you care a lot about concurrency while not caring at the same time.

Functional programming is great, but your CPU has registers and the way it works is closer to the imperative paradigm.