How does Compressor Quality affect RGBA Compressed ETC 2 Format?

In the documentation, there's a clause that says, "When using Crunch Texture compression". But according to the same documentation page, Crunch Compression builds on top of DXT. My Texture is on ETC2, so why is this option even here? Does it still affect my texture even if it is not in DXT format?

Using Unity 5.5.2f1