It's an expressive, pure, statically typed functional programming language with a large enough package registry, community and optimized enough runtime/compiler.

Breaking down the benefits of each:

- Expressive: you can model things with greater fidelity

- Pure: you know when your code performs side effects, so you're in for fewer surprises

- Statically typed: you learn about things at compile time, not in production. You also need to write fewer tests.

- Large pkg registry: fewer things to implement yourself (compared to, say, Idris)

- Large community: fewer problems you'll be the first one to discover/solve

- Optimized enough compiler: compile times can be _acceptable_

- Optimized enough runtime: your app will be fast enough without you having to care much about it

Now one point that isn't obvious from all this and that is a big selling point for my company is how much of a breeze refactoring is. Types give you more guarantees around how your code behaves, so there's classes of mistakes you can't make, and won't have to rely on a super strict test suite to prevent you from making.

Newhire submitting a PR changing 25 files all over the codebase? Business as usual.