Errr - doesn't it come from the people buying the Assassin's Creed games? That particularly series earns hundreds of millions of dollars each game, and at least some of that value is created by the engineers modeling the character's hair.
The world would be culturally poorer without music, art, etc., but it would still function. That's not true if you got rid of those other industries.
If I get a haircut, that's not valuable to at least 7 billion people worldwide, but it is valuable to me, so it is some positive value created.
In a similar manner, if a million gamers like some game (or a satanic black metal song) and the whole of bible belt does not, well, that's a lot of positive value created anyway; assuming no actual negative externalities where someone else gets harmed by it. Individual value is subjective, but it can be aggregated - if you consider that playing a particular videogame has negative value and don't play it, then the impact is zero; if I consider that playing the same game has positive value to me and do it, then it adds a positive contribution to the global value created; I got something I liked, and that's valuable by itself, asssuming noone else got hurt by this.
Do you also believe the Rolling Stones didn't create any real value?
Just because people pay money for something doesn't mean it adds value or creates wealth. Rolling Stones is a tough case, some entertainment is necessary, but at what level and cost is up for debate, it's not like I have all the answers.
If people prefer hearing a song over getting an (extra) loaf of bread, then hearing that song is by definition more valuable (more valued by that person) as that loaf of bread. There's not much debate needed about Rolling Stones - millions of people have expressed their values, and their choices illustrate that the music of Rolling Stones is literally more valuable than a billion loaves of bread; people have intentionally allocated a billion bread-loaves worth resources towards Rolling Stones because they valued Rolling Stones more than other alternatives.
People paying money for something doesn't necessarily mean it adds value or creates wealth, there are all kinds of edge cases like fraud, exploitation, addiction, etc, but in general, in the vast majority of cases it does mean exactly that - if people genuinely freely wanted to pay money for something and did so, then that's very informative about what they actually value; this is far more informative and truthful than, for example, what they claim they value.
That's why the idea is being disagreed with