by and large these things worked on paper/transparencies I would presume.

You have to presume because you weren’t involved in helping the people who were used to doing everything on paper learn how to turn on a computer. Do you think people in the past were super qualified and just magically knew how to use a computer in the past? Nobody ever needed help loading a file on a floppy disk and printing it to paper so they can present it to their boss?

There have always been clueless bosses and tech people that had to make things work. If you go back further, why do you think they all had secretaries typing things up?