[...] in the same way as management speak isn't around in order to be elitist, it's there cos we're overpopulated and need to create jobs for people.
To attempt a quick summary of what I reckon re: management speak from my giant ramble upthread: it exists (or at least continues to exist) because it does actually confer benefits from above. It's like a covert / unstated performance indicator for those trying to climb the management ladder.
Not talking about the really egregious examples, but the use of things like "facilitate" not "chair" / "run" a meeting, "going forward" not "from now on", "challenge" not difficulty, "issue" not "problem", "learnings" / "takeaways" not "lessons", "offline" not "one on one" / "after this meeting", "I hear what you're saying", "I'd like to acknowledge" etc. etc. If you can't do this stuff and you want to be a manager, that's a challenge that you need to address.
The thing about hiding what you're doing is that there are those who do that in all situations - to attempt it they usually try on the register / tone that's right for the situation. So if they're managers, of course they'll use management speak. But that doesn't necessarily mean that's why that stuff exists.