nushell feels like a pretty good in between of the two. I'm still going to use fish tho.

This is wrong. Their framework uses metal, which is an apple only graphics API.

They're using metal which is Apple only.

For the last point, they mentionned from the very start they wanted to go open source

That's not the point of the article though. Reversing an array is simply an exemple of a very simple CS puzzle. Of course it's common enough to have a builtin function. No, this won't be written in a code base, or asked for a code review. That's not the point.

Interesting!
I see OCaml with rust syntax, for the web, which checks out the project goal of bringing functional patterns to everyday programmers.

This is very cool

Yes, they do...