I used to be a grocery checker.
Long ago, there were NOT scanners & UPC’s.
With the introduction of such time saving & higher accuracy implements, the individual markings were no longer needed.
IF there is such a law about 85% of all items being marked individually, this part of the Calif law needs to be reversed.
Technology has passed it by.
Good points. Also, checkouts didn’t have video display terminals, where the customer can see the prices when items are scanned. I don’t hesitate to refuse a purchase, where the price isn’t what I expected to see (based on the shelf tag).