This was a question that came up with my recent video on Book Scanners (I think it was one that many people here watched to discover the community).
Usually, when I publish a video - I'll get a variety of comments. Mostly nice ones. However, I'll always get some free advice ones too. "Why not ...." or "You should...." etc.
On the book scanning ones - I always get the "That's against copyright law!" (spoiler: it's not)
Many people also say "Just use your phone".
So I just released a video comparing the phone to a dedicated scanner.
Another spoiler - they both work - there isn't a "must-use" winner. Although, I have the scanners and use them a lot :)