I didn't say that they stayed the same. The point is that you can't say objectively that these arts have progressed any more that you can say that human nature has changed for the better.
What I'm saying is not an unusual opinion. I mentioned electronic music, so it should have been obvious that I'm aware that "things have not stayed the same". But the point I'm trying to allude to is the fact that art is an expression of the human spirit, and because of that, it doesn't advance like science or technology.
Here's an example of someone writing in the Guardian:
"It was a year of revelations. The oldest portrait in the world – carved out of mammoth tusk 26,000 years ago in Moravia – had a long slender face, almond eyes and a rueful half-smile: just like a Modigliani. She came to the British Museum along with Ice Age drawings and sculptures so superb they have never been surpassed, proving once again that there is no progress – only change – in art."
From
https://www.theguardian.com/culture/2013/dec/22/art-review-2...
Or, on a slightly different point:
"It is obvious that art cannot teach anyone anything, since in four thousand years humanity has learnt nothing at all." (Tarkovsky)
Tarkovsky obviously isn't denying the growth of scientific knowledge. He just thinks there are aspects of human nature that only change slowly, if at all, and that those aspects are more significant than the accumulation of scientific knowledge and all the changes that brings about.