Great question!

Many design folk have told me, in conversations on Mastodon, that there isn't a good word to replace "content" for the jobs -- jobs that inherently involve thinking about the relationship of form to content, container to content, etc. I think this is a good point, and the people with the most genuinely organic need to use "content" to describe human expression are essentially those like you. Also, I don't think designers/UX folk/etc using "content" in their jobs are mostly to blame for this phrase creeping into daily parlance. Nobody is forcing someone who writes or wields the moving image to call themselves a "content creator"; if they want to snuff out the flame of human civilization, lol, I guess they can go for it, though my goodness I wish they wouldn't. This essay was aimed heavily at folks like that!

So, one could argue that there's no need to change your title. It has a specific industrial meaning and a specific industrial purpose.

That said, it'd probably be good -- in the everyday prosecution of your work -- to, whenever possible, talk about the stuff that people write on Medium using the specific words that apply: Essays, memoirs, explainers, what have you. Even referring to a "post" and a "comment" is more specific than "content"!

You may already do this in your daily work, and so I doubt I am telling you anything you anything you don't already know and do, heh