I've definitely thought about some more mobile mechanics for auto tech, and how cool it would be to be able to work up to a mobile rig, but for this post, just the tires.
Changing tires is simple. Most everyone who drives can do it. A junior mechanic can definitely do it. So instead of a junior mechanic having to puppet request for a tow, for a vehicle with one blown tire, why not just have the dang junior mechanic go out and change the tire himself.