What makes Linux appealing to me is the extent of customizability, but I didn’t find many answers when looking up with desktop environment is them most customizable. Some say KDE is most customizable than say, Gnome, but doesn’t Gnome support CSS customization while KDE doesn’t?
No added extensions, just default, id go with plasma, with extensions right now daily use Gnome (but without extensions its bland af, it really needs them and I wish it had more)