Keyboard shortcuts don't have the discoverability of a menu interface but are good for power users. Ideally they would complement each other.
I really like the ergonomics of pie menus, though my experience is limited to Blender. Navigating linear menus require more fine movements than flicking the mouse in one of 8 or fewer directions. And the direction of mouse movement becomes muscle memory the way a keyboard shortcut does. I find a pie menu works well in a mouse-heavy workflow like 3D modelling. But there are definitely applications where it wouldn't be the right fit.
I really like the ergonomics of pie menus, though my experience is limited to Blender. Navigating linear menus require more fine movements than flicking the mouse in one of 8 or fewer directions. And the direction of mouse movement becomes muscle memory the way a keyboard shortcut does. I find a pie menu works well in a mouse-heavy workflow like 3D modelling. But there are definitely applications where it wouldn't be the right fit.