The UI is inconsistent, esp. wrt the menu bar. Keyboard shortcuts are inconsistent across different apps. macOS remembers window positions, GNOME doesn't. macOS can use different backgrounds for different monitors, GNOME can't. The GNOME Panel is a poor substitute for the macOS Dock (which itself is severely limited) i.e. doesn't offer any visual cue that an app is launching. I could go on.
OSes are a tool. Use what works best for you.