One difference is that you can decide to stop wearing your seatbelt if we learn at some point that seat belts are actually more harmful than helpful. Rather th

One difference is that you can decide to stop wearing your seatbelt if we learn at some point that seat belts are actually more harmful than helpful. Rather than saying if we mandate one thing, we should mandate everything, we could just evaluate each of them individually. And since that's what we actually do, and these decisions are made by different people at different times (because of elections, appointments, etc), some inconsistency seems inevitable.