Feel free to un-buckle your seatbelt and use one of those plastic bypass clips on ebay. After all it's extremely unlikely, statistically, that you'll crash, and the seatbelt is a slight inconvenience after all......I agree with you!
Could cause... but in witch scenario? Of course the driver have to be behind of wheel and pay attention!
When I come out of the house COULD: I can stumble over something ... I fall head over heels or the corner of the house and that's it.
This is likely illegal to use on UK roads as you cannot (currently) demonstrate you are in control of your vehicle if your hands aren't on the wheel. It's likely to be used by people who want to use their phone while driving or film themselves putting a sack of potatoes on the drivers seat and climbing into another seat.
it only takes one idiot who choses to use a device like this so that they don't have to pay attention to injure themselves or other people (or a brand) so let's not sell or promote devices that are designed to bypass a safety feature, irrespective of how likely or unlikely they are to cause injury.