That's why I chose it as an example, they show up the difference between a well made tool & a badly made one much more obviously. The cheap ones can't even cope with brass nuts.
There's little point in making them without the edges parallel & smooth either but a quick glance in the junk box provides plenty of examples of both. There's no definition of what CV has to be, other than some CHrome & some Vanadium. The softer you make it the quicker & easier it is to manufacture.
I don't assume they aren't, I've found that sometimes they aren't, wheras that's extremely rare with a QA approved manufacturer.
They're an expendable item that wears out quickly, the lifespan is extremely dependent on the original size & the heat treatment & alloy, the unbranded ones literally last less than a 10th of the time of Stanleys or Wera's. Or come to that Tengs, which are more expensive than Stanleys.