Sadly whilst many of these are good for "writing less code" -- and as I'm always saying "the less code you use, the less there is to break" -- JavaScript arrays are extremely slow performing. Likewise adding the overhead of callbacks with the various each/every/map functions only drags performance down more.

... and don't even get me started about the painfully cryptic code of arrow functions that can leave you scratching your head if you come back to the code after a year.

You've got some good advice here, but people need to be aware of the performance hit this "more convenient code" brings with it.