The big advantage of paper maps is that they give the-big-picture, better so than phone or standalone gps units. State level maps are also good at highlighting major routes, with limited information on minor roads or "scenic" ones.
Years ago for bike ride from Mpls to Chicago, I had to order county level maps from Wisconsin to get info on minor low traffic roads.
And later for an Alaska trip, I made heavy use of detailed guide books. And in the lower 48 I also used AAA books and maps.
Still I have been surprised by paper maps. One straight route in southern Oregon turned out to be heavily washboarded gravel. And in the mid 2000s there was a big news story about a couple lost in the Oregon coast mountains after Thanksgiving. There was a lot of speculation about them using Mapquest, but it turned out they'd used a paper map, where the route was marked aa paved but scenic (BLM and FS).
Sometimes the only clue on paper maps that a route is mountainous is the color of National Forests.
We have a lot more information available to us now than a couple of decades ago.