With chess, there is a known, specific end goal, and the "creativity" comes with how you arrive there. With an artwork, the end goal is entirely decided by the artist, there is no "win state" to reward.
That's not what people who play chess thought. The creativity wasn't in the goal, but how you arrived there. The "beauty" of the steps that you took on the way to the goal. They believed that it was human creativity and sense of beauty that would never be encapsulated in a computer program. They turned out to be incorrect, but maybe you're right and things are different in a wider domain, we'll see.
Not sure exactly you mean, or who you are referring to as being correct. Not sure the relevance of anything being a game, the question is the intersection of computation and interacting with humans. Having been there at the time, I saw the snide dismissals of computers playing chess, they were "simply playing by rote", they were just glorified calculators who could never understand the beautiful moves played by human grandmasters. And this was actually true at the time... it just didn't stay true.
Today, very many humans enjoy spectating computer played chess games, and often comment on the "beauty" of the moves played. Take that for what you will.
