In 1979, I doubt copiers were 'increasingly obsolete'; I'd expect the market was growing rapidly. Laser printers, email, the Internet, didn't yet exist; PCs barely existed, and not in offices. Almost everywhere would have used typewriters, I suppose.
>Laser printers, email, the Internet, didn't yet exist
Actually, all three did; the latter was in the form of ARPANET [to be technical, not "The Internet"].
> Actually, all three did; the latter was in the form of ARPANET [to be technical, not "The Internet"].
True, but a technicality. Very few people knew they even existed, and they had zero impact on Xerox copier sales.
Does not mean they did not exist. See citations, below:
https://en.wikipedia.org/wiki/Laser_printing (see 2nd intro paragraph)
https://en.wikipedia.org/wiki/History_of_email (see 3rd intro paragraph)