"This piece borders on political correctness" is an excellent critique of what I'm doing here; language prescriptions are perilous territory! If people are using a word and they're happy about it and it's useful for them, it's weird and paternalistic/condescending of me to suggest they change. I, personally, as a journalist, tend to avoid vogues for any prescriptive use of language, because I think it's crucial to communicate with people in clear, vivid and specific ways that they already understand.
You also make an excellent point about "content" have a clear and specific meaning in the industrial context -- design, UI, and the like -- that you're working in! When this essay went live, several designer friends of mine on Mastodon argued that in their work, "content" has a clear and specific meaning. Their craft and art are all about the relationship between form and content, between the tool for communication and the quantum of communication. There isn't really any word better than "content" for them.
I agreed with this, so I added that cavaet at the end of the piece!
But in large part -- and I think it's my fault for not making this clearer -- my argument is aimed at the mainstream world outside of design, UI, UX, and the like.
It's out there -- in the everyday world, where writers and filmmakers and animators and actors etc are doing their work -- that the use of "content" becomes both weirdly inspecific and, in the hands of C-suite "creative industry" executives, deeply weaselly.
Once we turn the lens to how everyday people normatively interact with content on a daily basis, the word becomes uselessly vague. Nobody, upon entering a bookstore, thinks to themselves "I really want to see some content". Nor when playing a video game, nor when going to see a film; nor, I think, even when opening Tiktok or Youtube or Instagram. Nobody who comments on a Medium post thinks to themselves, "I should add some content here."
Part of the reason I'm agitating against the widespread mass use of "content" is because I am trying to honor the final injunction in your post: Let's call things as they are -- essays, films, comments, posts, videos, jokes, tweets, novels, and more. In everyday life, at least! Designers have an industrial reason to use "content"; the rest of us don't.
Despite the genuine risk -- which you neatly identified -- of my essay here veering into finger-wagging territory, I do believe that the metastasization of "content" beyond the confines of the design industry is a small (quite small, really, but nonetheless significant) piece of the long-brewing decline of respect for the arts.