30 years ago, you could pretty much rely on the Brand name to take comfort in the quality assurance of a product. In the 70's, Sony made great consumer electronic products. Vivitar made very good camera products. And so on and so forth. But in the 1980's, industry began using OEMs. (Original Equpment manufacturers) Meaning; some sweatshop in China, or Korea, made a plastic lens that they would sell to vivitar, Olympus, Nikon, etc....... because it could be made cheaper and quicker. In some of the worst situations, companies like Sony would buy very mediocre consumer electronics from Korean OEMs and put their prestigous label on them.
The consumer would think that he or she was getting a stereo that was made in the same plant where flat screen TV's were made. The truth is, the low end consumer product had nothing that came from any sony manufacturing plant.
By the time the 90's came around, brand name became more valuable than the corperation's net worth. By the turn of the century, the only principal you could be sure of was that brand names could no longer be trusted.