I will say scanners are somewhat unergonomic, but if you had a high enough definition camera, you could photograph the document in its "natural environment". Granted, it's harder to get an evenly lit picture that way, but I think it's a nicer interface.
Scanners with automatic feeders are ergonomic when you have to scan more than a page or two. Just place your stack of paper in the feeder and press start. I had a job where I used to do that routinely, and no way a camera would have been more convenient.
All of my document "scanning" for the last—god, maybe 15 years?—has been with a phone camera.
Before everyone just started using Docusign anyway, I'd bought houses with a phone "scanner". LOL.
I don't think I started with it, but for a very long time I've had an app called TinyScanner that's good-enough at edge detection, can de-noise or make a document entirely black & white, and can glue multiple pages together into a PDF. The results look better than plenty of flatbed scanner results I've seen, if not as good as the best of those.
Fair enough, I actually have been thinking about this topic lately since I have to generate and print and fill out and sign a lot of paper vouchers in my job. I would prefer having a dedicated scanner to just throw them into in a stack with a server/cron job/bash script always watching for new incoming documents rather than a more complex camera setup but yeah something like a camera over your shoulder on your desk could pick up documents too
