[djfm]

No offense taken.

I said I like to write it this way, not that I always do it.

> why code like that

It's a fun exercise.

> it would be a huge waste of time and energy

I don't fully agree on this: from the name and signature it's pretty clear what the function does, so you don't need to waste time "parsing" the details. And with unit tests it is also very low-risk.

But that's speculative, in a real project I'd just use lodash.