Decades of innovation that have been invested, not to make a better product, but mostly on how to extract more and more money from their victims, I mean "customers".
I would like to own a printer again, but for printing something like once a month, I just can't financially justify spending several hundred bucks on a device that might, at the whim of the manufacturer, decide that the way I'm using it is not okay anymore, is probably designed to break after two years, requires me to sign up for a subscription service for ink, or whatever BS else the decision makers in this space come up with.
For printing something like once a month, it is even harder to justify wasting space by putting a printer. Printers should be put around in form of vending machines which would let you you insert a USB stick, drop some pennies and print the PDFs.
However, I'd not want to be the device manufacturer, making it secure against all kinds of USB attacks