I think that if you poke at the term "rent-seeking" with the definition of "middle men who add no economic value yet inject themselves into transactions", you'll just end up arguing about what "adding economic value" means.

That said...if you can do that, you'll probably find that some additions of economic value are far more defensible than others, so it shouldn't all be flattened in the manner you're suggesting.

I mean, scalpers add economic value, right?! They allow (wealthier) people who didn't stand in line at the right time to have a chance to purchase a ticket!

Yeah. “Rent-seeking” is just a fancy rhetorical term for “people doing things I don’t like with money”.

Subscriptions are rent-seeking. Loans are rent-seeking. Spending millions in capital to buy a building and renting apartments for thousands? Rent-seeking. Copyright and patents, for sure, unless an AI company is involved in which case copyright is noble and must last a thousand years, because AI companies are rent-seeking.