I think so. Peanut butter is super high in calories, protein, and fat. These are obviously the main nutrients you need to be aware of when undertaking strenuous physical activity like a thru-hike. Two tablespoons of peanut butter has 190 calories, 16g of fat and 7g of protein (source). There are few vegan foods comparable to the nutrient density of peanut butter. Non-vegan hikers of course eat a lot of cheese and some eat meat.
I ate peanut butter on my hike for lunch almost every day. Sometimes just by the spoonful, but usually with a bagel or tortilla. And sometimes with chocolate chips when I had them.
When I could find it, I preferred the “natural” varieties from the big companies like Skippy. They don’t have partially hydrogenated oil like most peanut butters do, but they still have a little sugar in them so they’re tastier and easier to eat daily.
Maybe you’re thinking, “really? peanut butter? tell me something new.” I believe these kinds of foods are important to affirm for vegan hikers. The reality is that most long-distance hikers–vegan or not–are surviving on an extremely limited variety of food. Most hikers carry cheese as an easy, calorie-dense trail food; peanut butter is a very strong alternative.