I met a guy who didn't wear his seatbelt. He was a delivery driver and in a collision at 20mph. His head went through the windscreen and it scalped him from the eyes up. He had a scar all the way across from ear to ear. He couldn't shut his eyes for months. He wears his seatbelt now.
I would rather we don't have to spend precious emergency responder time on preventable injuries and deaths that occur at much higher rates by people not wearing seatbelts. If we can require you wear glasses to drive, we can require you wear a seatbelt as well. When someone dies in an accident because they didn't wear a seatbelt, there is another driver who now has to live with the fact that they killed someone.
Your answer does not refute anything that I said. Because judging from your reasoning, we should ban McDonald's and other bad food, so that people would not get heart attacks and die, so that we wouldn't waste the precious time of first responders, when they could rather attend to other people who actually want to live - those who don't eat poison
If I'm in McDonald's and a fat person enters that does not increase my chances of gaining weight.
If I'm driving and a driver not wearing a seatbelt enters the road it does increase my chances of being in an accident because if something happens that makes them have to swerve sharply, such as a large animal leaping into the road in front of them, a seatbelt increases the chances they will be able to remain in control during that maneuver.
According to the CDC in the US every year 800k people suffer from a heart attack. It could happen while driving. While it does not increase your chance of gaining weight, it increases your chance of getting in a car accident, because that other person might be driving while having a heart attack
One of the primary aims of seatbelts are to stop you becoming a projectile and protect other occupants of your car and people outside it. It's not just a personal choice.
Me and a lot of people wear them purely out of fear of being robbed by the state