Because your refusal to wear a seatbelt presents no risk to others. But vaccine refusal does present a risk. So the stakes of the game are not the same.
"X poses risk to others therefore you have no choice" is a statement that can be made for nearly any scenario. To wit:
Uncontrolled flying bodies pose additional risks when there are multiple people in the vehicle. There's also the risk of driving to begin with, for people both in and outside the vehicle.
The risks of harm to you _and_ others from crashing a car are probably higher at this point than that of a vaxxed person getting seriously ill from covid.
But anyway the point I was making was to refute GP's statement that seat belt laws and the pushback around them are the same as for the vax mandates. They are not, because the vax is permanent, and the consequences for non-compliance much higher. The fact that you can't "take the vax off" is part of these stakes that are not the same.
Refusing to wear a seatbelt does, in fact, present a risk to others because in a crash, you can become a lethal projectile should you fly and hit someone else.
Every time someone is unbuckled in a car crash, there is a high risk they will hurt others. Someone in the back seat could fly forward and hit the driver, for example.
