Uniqlo is using RFID too at least in France. Both work pretty well and the speed of checkout is unmatched. But this works for Uniqlo and Decathlon because they

Uniqlo is using RFID too at least in France. Both work pretty well and the speed of checkout is unmatched. But this works for Uniqlo and Decathlon because they only sell their own products. Supermarkets come with more hurdles, as products don't typically have any tag attached and are also selling bulk. I also suspect you need an average price per product that's too high for supermarkets to make it worth it.