As others have said, paper maps much better for general overview and planning and always carried as back up even if using GPX files, but tbh, much prefer a paper map rather squinting at a tiny screen.
Also, always look at road atlas before following SatNav — try it sometime and you might be amazed at some of the routes a SatNav tries to send you on!!
By all means use a GPS but it’s essential to still be able to use a map and compass. Ever wondered why, if you do your ML or BC MTB Leaders award that you have to navigate with map and compass?