Your hard packed, easy dirt trail, and 95% of your overland travel, is perfectly fine for 2wd.........until it rains. Or snows. S10's and Ranger 2wd's are the reigning kings of upside down in a ditch during the winter around here. Tied with Prius's.
Wheelspin is heck on a trucks drivetrain. Sometimes I select 4wd, off road just to completely eliminate it, not because it's needed. Sharp gravel can eat tires when they slip. Ride can be a hair smoother in 4wd sometimes. I didn't bust my butt for all these years to settle for 2wd again.