Agreed, this is one of the common misconception of Gnome 3. Gnome 3 actually encourages keyboard driven workflow: "Ensure that every operation in your application that can be done with the mouse can also be done with the keyboard."[1].
They use 'big buttons' mostly for accessibility reasons.
Although I personally don't use Gnome 3 as DE because of lack of customizations, I agree to most of their Human Interface Guidelines[2].
Less of a gnome thing than a wayland thing, but it matters since not that many DEs support it yet.
Basically, after having moved to wayland I find it incredibly difficult to go back and use X on laptops.