I don't use that and don't think much of it to be honest. I think the artists have earned their money, that's why I always pay full price for the songs. I also attach great importance to quality, and a few days ago I got good subwoofers (Klipsch R-12 SW- Klipsch R-12 SW subwoofer in the test - subwoofertests.de) concerned. If you convert YouTube videos to Mp3, it doesn't sound so good in my opinion
As for the quality, you're probably right, but it's completely legal (look here). In any case, artists have more money than they can spend in one lifetime, they don't need more