Honestly, the debris isn't that oppressive to deal with. A lot of it isn't on the scanner glass, it's on the paper itself (smudges from my hands, lines that didn't erase fully, chunks of pencil wax that I didn't find and brush off the paper before scanning it) - so they'd appear on other capture systems. I clean the scanner regularly, it's just surprisingly hard to clean it 100%.
Given I normally need to touch up a bunch of stuff anyway (clean up text, make the white parts pure white, tweak some wonky lines, make pupils pure black) the debris isn't much of an issue, I just clean it out as I go, it's just always something I need to check for in the scan, so I'm always doing some editing when I convert my analogue media to digital for web. I think the results can look really good though.
I'm not hugely familiar with document scanners (and they've come along a long way in recent years) but in my previous experience with camera-based systems, you don't tend to get great colour accuracy from them unless you have a very expensive system. They'd also mean setting up an extra device in my cramped living space. I do have a cheap "document scanning camera" that livestreams video, and it's really nice, but the colours are always a little washed out.
Cameras have all sorts of other issues, alignment is the big one, getting your camera to be not-tilted is pretty rough, and a high quality camera for capture can be pretty expensive. The colour replication in my (modern flagship most expensive) mobile phone is surprisingly bad, and it's not possible to turn off image processing without jailbreaking the device.
On the other hand, a cheap flatbed scanner can be part of a printer combo, and it can scan with really good colour replication, It also lets me scan at 1600 DPI - which makes a HUGE high quality image. This is great for editing, you shrink it as the final step.