Both paper and digital maps have their pluses and minuses, and in a given situation, one form may have advantages. I like the fact that paper does not require batteries and can be easily viewed in bright sunlight. A paper map will continue to function after a salt water dunking, unlike a phone. In an emergency, you can trim the margins of your paper map and voila! - tinder for your fire (my frequently used maps are often coated with some sort or another of 'Map Goo" which will burn quite readily).

Many recommend that you carry both - they aren't mutually exclusive.