I personally find a GPS unit (or, now, a GPS app on my phone) to be way more convenient than a map. Safer, too, since I can pay more attention to the actual driving.

Sure, but the original point was about need, not convenience. Personally, I use google maps on my phone, since it's always in my pocket anyway.

"Need" is a difficult word to work with, here. Do you "need" electricity? Your ancestors got by fine without it. Beyond air, water, and food, you don't really need anything.

Also basic shelter. Often underrated when blocking out needs.

I have several in my car, and I make use of them. I find they are great for navigating freeways, but GPS is better in-town, particularly for locating an arbitrary house address or a business by name.