A huge difference between seat belts and masks.
Seat belts really do reduce your risk of being injured in a crash, and if you are injured, they really do reduce the severity of the injury.
These masks do not do shit to protect anyone against any virus. They do not reduce anyone's chance of catching any virus. They do not reduce anyone's chances of spreading any virus. They do not reduce the severity of the results of catching any virus.
They do not do anything except give a false sense of security and virtue-signaling to those who are stupid enough to believe the bullshit that they've been fed.