Why is that a thing I would do?
Fair question. A few examples:
Let’s say you want to send something to a printer, but don’t have network access to that printer. Something at a client’s office, a different firm location, etc. You could build a webform, and anyone could upload a file, select a printer from a dropdown (maybe password protect that one).
Or every time a client schedules an in-person meeting of a certain type, a print job is sent with all the goodies you need for that meeting.
Or each time a type of project reaches a certain status, a deliverable or mailing label is printed.
Or every time you receive recurring email X, the attachment needs to be printed.
It’s an elegant solution to a problem that shouldn’t exist in the first place.