I visited a contact center for a major-ish online retailer once for work, and watched their processes. They had people dedicated to chat, who would operate 5 or more chats simultaneously, and in general were typing rather than copy/paste iirc. I'm sure it happens though, these guys I visited were pretty low tech.
It's often easy to see the copy paste variety happening though, e.g. in email discussions where you get sent some wall of text that's barely applicable to your situation. I've had this happen a lot with amazon and uber.
I don't mind the pre-programmed walls of text, but please don't make them too big. I got a wall of text answer out of Garmin--which promptly scrolled much of it off the screen. Unfortunately, what was left (in the window they constrained the size of!) was a coherent whole that was completely irrelevant. The relevant part had scrolled off fast enough I didn't realize there had been more.
(And I never did get anything useful out of their support, but they ended up fixing the bug.)
It's often easy to see the copy paste variety happening though, e.g. in email discussions where you get sent some wall of text that's barely applicable to your situation. I've had this happen a lot with amazon and uber.