Just today I had the disk usage analyzer (baobab) open and I was navigating inside directories so I want to go up a directory and clicked on the "<-" left arrow in the headerbar, which went "back" a screen, discarding all the work done scanning the filesystem.
If this app had a traditional menubar and a toolbar this wouldn't have happened.
This is a common type of experience I have every time I use a Gnome app. It almost feels like someone deliberately researched how to make desktop apps as counter-intuitive as possible and implemented that as the policy for some reason.