I think the biggest sign that tyrebands do not offer any significant safety advantage to normal cars is the fact they haven't been made compulsory by governments. Just for comparison consider, dual circuit braking, and ABS, and more recently lane assist, speed warnings, and several other driver assistance aids which are now compulsory. If tyrebands were as effective as the manufacturer claims, such devices would have been included, but the legislation has gone for TPMS not tyrebands. This is about as strong official signal as you could want.