It's more capable. Autopilot can basically do 100% of highway driving from on ramp to off ramp. It can switch lanes, and it can also take an exit from one highway to another highway.

Either way, without data about how often people use each driver assist feature, it's not scientifically rigorous to assume that each system is used exactly in the same proportion. The NHTSA should have made this caveat very clear, and should have released data from Tesla about crashes per miles driven if it's available (even if it's not available for other automakers).