Vendors have no idea on how to use them. So they crank out the same old conforming figures.

There are lots of vendors who have created dynamic clothing for Poser: Karanta, Tipol, Biscuits, Frequency, Nerd3d, Lully, Esha, Kaleya, adh3d, Leilana, Nirvy, Yaneelis3d, Leilana, threedplayer, sshodan, Vyktoria, Fugazzi to name just a few. Many of them include workflow and/or tutorial on dynamic clothing.

Hybrid clothing would be nice though (partly conforming and dynamic)