When you have dealt with as many collisions as I did in my former career and watched non-seat belt wearers die , you don’t need any convincing to make you and your passengers wear seat belts.
for all the know-alls whinging about fire, drowning etc, these sort of incidents are very rare and account in most countries for less than 5% of collisions. You stand a much better chance of survival and escape if you are wearing your belt when it collides and catches fire or enters the water.