It's honestly not a big cost once you become an advanced user of it. I've been getting paid to do pure FP for like 5 years and the language rarely gets in the w

It's honestly not a big cost once you become an advanced user of it. I've been getting paid to do pure FP for like 5 years and the language rarely gets in the way. You can pick how statically correct you want to be, and refactoring in one direction or the other tends to be rather mechanical. And when it isn't, there's typically something interesting there anyways.