Disclaimer: when I worked on Internet Explorer in its twilight years I built a fork of BingBot that surveyed JS API usage and delivered a report to a Partner-level SE, whom I was in awe of, that I shared a team-room with.
In my experience, Array.prototype.shift() had limited applications because it mutates the source-array. I gathered it exists because at the time it was specc’d in the late 1990s the other cool kids, bash and perl, both had had args shift and JS didn’t want to feel left-out.
How different would the world be today if Array.prototype.shift instead froze the array and returned a reference to a +1 slice of the array instead? There was a fantastic opportunity to introduce FP and immutability to a whole generation of software people - which we (as an industry) squandered to our detriment. Ultra-new languages like Go and Zig still default to in-place mutable data and it’s maddening!
What hath shell scripts wrought?