[mercer]

> This reminds me of Ruby's return-the-last-evaluated-thing-in-a-function semantics (which sadly Rust copied). Having to type one extra word is not such a burden that you should add cognitive overhead each time someone not intimately familiar with the language has to read your code.

I think the concept of returning by default is fundamental enough that doing so or not is mostly a matter of what you're used to. If I'd started out with Elixir or Ruby I'd probably find it strange that I have to manually return stuff from a function.

Furthermore, at this point ES6 is common enough that knowing at least some of the core additions (among them arrow functions with their implicit return) should be something any front-ender knows.