Around 2000, I spent over a month one summer driving around the US with camping gear, a stack of AAA maps, AAA books for each state listing campgrounds, and no plan other than to see interesting things like national parks. I drove around 10,000 miles. Most mornings, I spread out a map on the picnic table and figured out where to go that day and where I would be able to sleep or shop if necessary. No GPS and a basic analog/digital cell phone that kind of worked (analog, $0.69/minute roaming) in most non-mountain areas. It was an unforgettable experience. It's a shame if newer travelers are unable to experience some of these things.
As the driver found out, USA atlas with 1-2 pages per state should be in the toolkit purely as a backup map. AAA still has good state-level paper maps that are usable for everything except in-city driving and are good for trip planning even with a GPS.
On most trips, I still try to carry the state-level maps and usually use them a couple of times for something. I have yet to see a good way on a small-screen phone or GPS to answer questions like "how far away is the coast," or "how much out of our way would it be to go to that town" or "what's the next sizable town within 2 miles of the road we are on," which a glance at a paper map answers. GPS will tell you the closest town but it may be way off your route.
I do think GPS has been a big benefit for safety. Reading maps while driving was never safe but often necessary before GPS.