I don't know about you , but I hate it when the lady hits the brakes and I slip off the seat. OWWW!
When I was just a puppy she put an end to that by getting me my own seat belt. Now the routine is jump into the car, stand while she puts my harness on , she then attachs it to the seat belt, and then off we go.
Humans buckle themselves in but often forget how we become a flying object in a wreck. Buckle up for safety, it is the only way to go!