I have not taken data recently but one certain name brand manufacturer used to rank its products, sold the best one under its own brand name, second for OEM, and the rest for "dumpster".
I would think, if it does not bear company's name or does but it is an obscure company, there is no intensive to make them reliable and long lasting. Only motivation is to sell as many as one could, as fast as one could.
I have a packages of cheap parts to experiment with and use in emergencies. I check them against calibrated sources to check its value before putting them in a circuit. If it is anything I care, or a final product, I buy name brand from top shelf companies.