> On GNOME you cannot minimize windows at all if I remember correctly.

This is incorrect. You can minimize windows on Gnome, but the button to do it is hidden by default. It can be re-enabled in Gnome Tweaks, and there is also a keyboard shortcut (Super+H) for minimizing.

Gnome is however indeed fairly workspace-centric.

As for customization, out of the box Gnome is quite rigid, but its extension ecosystem far surpasses that of KDE. You can use extensions on Gnome to for example get a dock or system tray back.