I'm not sure about the art and music making. Computers will make this too and not just better, but also personalized for your brain. I think, there will be a great depression, when even creativism becomes boring.
No it isn't. Not anymore ludicrous than automating anything else, just far more complex in its implementation. It's not impossible.
>the universe we live in is infinitely vast and full of endless paths to explore.
Yes, but human beings are not infinite, nor is their capacity for creative thought. We're bound by finite time, space, perception, culture and neurology. Therefore, I believe human creativity is a process which can be modeled, replicated and mass produced just as human labor can. There's nothing special or magic about it, it's just a nut we haven't cracked yet. But then, there was a time when the concept of a machine doing math was unthinkable as well, and a machine doing cryptography, and a machine playing Jeopardy, etc.
Consider how formulaic much of modern popular culture is. Do you really think it's impossible for an AI, with access to the entire web and, theoretically, working neural models, to churn out an acceptable dime store novel or movie or video game? We're not talking about genius, here, we're talking about commerce. People will buy it. And if people will buy it coming from a machine, there's no longer any reason to pay humans to generate it.
It doesn't even really have to be better than what humans would produce - just acceptable.
Although that does also suggest that human-generated creative works may become more valuable for their rarity.
Here is an expert who agrees with you, and has the results to prove it:
Yep. It's mine.
The entertainment industry has never been so big and it doesn't stop growing, so I guess the trend hints at the opposite. Electronic games weren't a thing 30 years ago, online games weren't a thing 10 years ago, both are now big industries.
I bet more in technology introducing new medias (e.g. Oculus) and aiding on better / cheaper / faster content creation than completely automating creative work.