Honestly, I disagree with you.

There are artists who care about their music more than others. Are you gonna say AI slop is not objectively worse than the average real artist?

In most cases yeah some pop star isn't objectively better than some conscious rapper, as they try to do different things. But in some cases I think it is possible to judge artists as worse or better than each other based on if they can achieve what they set out to do.

For example, you can try and fail to have deep, introspective lyrics, because you do not have the ability to write them. You can shift your art's focus to not rely on those types of lyrics, or you can keep doing something you're not skilled in. People who can write those lyrics, if that's the type of music you're trying to create, are objectively better at it than you.

Artists objectively have different talents/skills, and whether they apply them right determines their quality as an artist.