We can retroactively value art of the past using an individualistic philosophy, but that doesn’t change how it was valued in past. Artists of the past were considered good artists when they were capable of putting their own selves aside and allow God to flow through them. We now value their individuality, but they probably would’ve seen their individuality as their failures. It was a virtue to be objective rather than subjective. In literature especially we have are tons of letters between writers where they insult each other for writing in styles that are unintelligible to other people

I don’t necessarily ascribe to their views, but I bring it up because you said art has always been this way and it hasn’t always been this way