I have many original professional made audio CDs from the early 90s that if you listen them, there are a lot of skips. I watch them against a light and I can see many dots. Bought them in 1991, started to have this problem a decade ago. They’re with a gold dye
For audio CDs I never saw two layers of plastic, only saw that on DVDs. But I stopped buying audio CDs in the late 90s