I find having to actually move to be a pretty engaging part of the game. You have to find resources, and that might be dangerous. Vehicles and concrete help you maneuver more quickly, but have their own risks/drawbacks. Defending your base and setting up an outpost starts out as a manual task until you know how to do it automatically.

In simpler terms, having to do things the slow and manual way makes the fast and automatic solutions even more gratifying.