I use KDE but that is out of habit and preference I have used them all and they all have pros and cons. Debian doesn’t customize them at all so there is no Debian specific DE for stable or sid.
It’s all about how they make you feel using them. also the nice thing is you can use gnome apps on kde and kde apps on gnome so unless you super care about theme there is no down side.
Like my favorite scanner app is Document Scanner for gnome and when I’m on gnome my favorite text editor is Kate. Yeah you’re doubling your needed disk space for libraries but disks space is cheap and your going to use up more space with flatpaks anyway.