There is a marvellous booklet, published by the Social Affairs Unit in 2000, called the Dictionary of Dangerous Words. It contains modern definitions, provided by many great thinkers and Oliver Letwin, of words "which once meant something good and now mean something bad, which once meant something and now mean nothing or vice versa, or which have in some interesting sense changed". If the SAU were thinking of bringing out a new edition, I would recommend that little word "key" for inclusion.
I was looking at the speaker-list for an energy conference, and it was pretty much the same list as for every other conference on the subject, of which there are dozens a year. This particular conference was organized on behalf of the Institute of Economic Affairs, which, of all organizations, ought to have been trying to encourage alternative perspectives. I wondered how the organizers came up with such an uninspired and conformist list, and happily they provide an explanation on their website. Their "target list" is put together "following extensive research and consultation with key industry executives". And guess what: their list of speakers is chock-full with those same "key industry executives".
So I add the phrase "key industry executives" to those other abuses of English: "key workers" and "key stakeholders". "Key" is used in this sense to mean "the people (or things) that we think matter". No standard is provided by which this assessment is made. The implication is that it is self-evident that these people (or things) are clearly the most important. "Key workers" are to be contrasted with those unessential workers in the economy, "key stakeholders" with those whose voices need not be listened to, "key executives" with the other executives who don't know as much about or aren't as important to their industry.
And there is worse. The phrase "key civil liberties" is starting to be used more commonly. That would be to distinguish from the unimportant civil liberties, would it? The ones that we need not guard so jealously?
Incidentally, if you enjoy the deconstruction of those politically-correct constructs that have perverted the original sense of many of our words, another excellent, more recent book in this vein is Mediocracy by Fabian Tassano. His blog is already linked from here, but you will find the book well-worth reading too.