So, just to speak about the BEAM, which is the part of Elixir I am familiar with, I don't think any BEAM language will ever be a good goto language. The BEAM isn't good at general purpose computing. It's not particularly efficient at performing calculations or using memory. It's good at reliably performing as you increase memory pressure on your system (via message passing). You can scale a business to a decent size on a smaller number of fatter nodes (high RAM machines). Connections will keep pouring in and you'll get a consistent ms.

That said, you'll run into issues once you hit a certain level of scale. I've had to make patches to the BEAM just to keep us scaling, and I've never seen someone get away with stock dist. You pretty much have to rewrite pieces of OTP.

Now is Elixir ok for a CRUD app serving 10G of traffic? Of course... but this is also the age in which every language has a solution to the C10K(, C100K, and more in many cases) problem, and there are compelling reasons to write your CRUD app in Go and get better library support, static types up front (trust me, you want a static type system), and lower latency.

Personally, I'm bullish about Rust. With async/await landing, it stands a good chance of providing the same focus on safety and reliability while being infinity more flexible at what it can effectively. It's a better general purpose language. Also, the actor model (and CSP as well) aren't the end all be all of concurrency patterns. Rust only provides the building block (futures) so it's much easier to choose the concurrent pattern that fits best for your problem. You can sting a future using the actor model, so it's still an option, but you aren't limited to it.