The vast majority of applicants cannot code at all. And I mean that literally.
No, you mean that hyperbolically.
Not only does it simply not happen that "the vast majority of applications cannot code at all" -- this literally has never happened at all, in my experience.
What does happen is that you get a range of people on a spectrum. And yeah, a fair number of them can't code very well. They're slow, they don't see smart solutions, whatever - or are just plain sloppy. But that's quite different from "not being able to code at all."
As to those people who (supposedly) can't "write a function that adds two numbers or counts the number of elements in a list" -- most likely they're simply freezing up from the anxiety of being whiteboarded by a perfect stranger for the first time in a great while - or perhaps ever. (In fact that's exactly what happened to me, on my very first on-site interview after college).
Or that is to say: they haven't internalized -- and produced defenses for -- the (intentionally) awkward and humiliating ritual of the modern tech interview process.
And again, you should only be actually seeing these people once in a blue moon. Unless the people running your incoming "pipeline" are utterly incompetent, and are constantly feeding you a stream of unqualified candidates. In which case your companies much bigger problem a lack of engineers who are able to "ace" HackerRank problems in 59 minutes or less.[1]
[1] Which, lest be honest now -- basically can only happen after extensive time spent on practicing these problems in advance. Or that is, by blatantly gaming your hiring "filter".
And one more thing:
How, you ask? By ... dodging responsibility.
No - their jobs just have different metrics for "responsibility" than yours. That's just the way many businesses are run, whether you like it or not.
Inside the flat a fruity voice was reading out a list of figures which had something to do with the production of pig-iron. The voice came from an oblong metal plaque like a dulled mirror which formed part of the surface of the right-hand wall. Winston turned a switch and the voice sank somewhat, though the words were still distinguishable. The instrument (the telescreen, it was called) could be dimmed, but there was no way of shutting it off completely.