I find this looks goofy, but other than the lack of physical buttons inside, this is a dream vehicle for me. Most weekends I want to drive 4 people + 4 mountain bikes a 120 mile round trip including fast highway and rough mountain roads.
Agree that Elixir and Erlang lend themselves well to this style, but I strongly disagree that everything written in them does or that the languages help enforce this pattern in any way.
It's quiet the opposite really from what I've seen. Elixir places absolutely no constrains on when and how IO happens, and provides extremely useful primitives for shutting state between (VM) processes in otherwise stateless code. A library function that looks totally pure could, for example, boot an entirely different subsystem that fired a missile into the sun before providing a return value and you'd never know it if you didn't read the docs, or use one of many pieces of fantastic beam tooling to inspect the runtime state of the system.
This is part of what makes these languages pragmatic to work in. There are foot guns everywhere, but the VM ensures you sign into the foot gun registry whenever you use them.