I still have some old shop vacs and some filters for them, so they still get some use. That said I use my CTs for cleanup. I get the idea of not wanting to run real messy stuff thru them. My shop vacs have holes in the hoses now from debris over time. So I'd be a big concerned about stuff that could clog a hose. Also i don't want stuff that will make a real mess of the clear container on the cyclone. But still, over time, why have random vacs verses all the same and do all. I have the attachment kits that has tools for floor and such, it works well.
I'm not concerned about bags/filters. I have a cyclone, so that's better than the shop vac, and the CT bags cost less than Shop Vac filters, so not an issue there. As my old shop vacs die, I will just get rid of them. Maybe even buy another CT just for cleanup duties.
As a side, I have a CT on my table saw, somehow it has managed to suck in very large debris that I have no idea how it made down the hose, Long thin cut offs. Of course for really big stuff on a floor, they still sell brooms and pans.