My last 25 years were in the steel industry. At one point we made wire for arresting cables on aircraft carriers from Japanese steel. Steel for sockets would be a specialty steel and would depend on the mill not the country of origin.
Socket manufacturing is a very mature industry, all of them are going to be better than what you could buy not so long ago. So instead of looking at brands , look at what you want to do with the socket . Not all sockets are designed the same, some tall and thick walled, tough sockets , others are short and thin walled, handier but not as tough. If you are working on car you want the later, if you are working on a piece of machinery that the last guy impacted on , the former.
1/4 socket now have dimples, so I retired my various made in USA SAE ones without dimples and replaced them with a Gearwrench set. But when it came to the deeps, I went with Tekton as they were fully broached.