When I did catalog work a dozen years ago, the shooters in the studio would use roll film on 4x5 for shots that didn't require much enlargement. You had the capacity to put 3 or 4 shots on a roll with a small bracket to make sure your exposures were right, and you had the advantage of view camera movements. It saved a lot of money.
A 6x7 back on a Linhof STIV was my setup for product photography in the 80s and early 90s, it served me very well. Need a bigger transparency? just change backs. The customers appreciated the savings on materials charges, and for stuff printed in a magazine, even 6x7 is overkill.
I have a question - something that's puzzled me and I must be missing something. Nearly anyone who has a 5x4 camera more than likely has a 5x4 enlarger, right? (or at least is trying to find one!). Roll film backs come in a variety of formats/sizes and invariably cost ~$100 upwards. 8 shots to a roll of 120 probably $5 a roll, so ~65c a shot. 5x4 costs twice that per sheet, but overall cost is still low.
Why would someone not just use 5x4 film, and crop it to the size? If you only had a 6x9 enlarger etc I could understand it....
What am I missing?
Nothing. You got it right.
Warning!! Handling a Hasselblad can be harmful to your financial well being!
Nothing beats a great piece of glass!
I leave the digital work for the urologists and proctologists.