I haven’t seen any shops offering less than 53cm for screens sizes around here in recent years.
The Australian Government removed the legal definition of the size of an inch several years ago so someone could offer to sell you a three hundred inch screen and then deliver one that fits in your hand and if they hadn’t also specified a size in centimetres you’d have legal no basis for claiming it wasn’t what you ordered.
My main client provides everyone with two screens as a single 58cm screen is considered to be way too small. A student in one of my classes used over a dozen screens that size on a single computer.