How good are $2 DACs?

Interesting read. I read an article a few months ago about a blind test on streaming services at different levels of quality. Professional studio engineers were assembled since it was assumed their job was listening to music and determining its quality and they would be the best judges. They were unable to tell the difference in any of the services. The services were Pandora, Tidal and some very high end MQA providers. No discernible differences were heard. When they unblinded the test, well, it was a completely different result.