You don't fly down final approach looking at the GPS map, especially on a good weather day.
You don't?
Maybe you should.
Don't know what you fly but TBH I'm not sure our "GPS" display" would help that much, since you're
not looking at a "Topo" presentation, you're looking at symbology on a pseudo map, and in any event you may not even have MAP selected as a display due other requirements....like using another backstop option such as monitoring an active ILS/navaid ....
In an ideal world, with clearances in hand and everything configured umpteen miles out I'd agree that a glance at MAP
might be a useful tool for a gross error check ( but then again there's still the odd case of MAP shift).