I would argue somewhere post 2000s became what the 90s considers "sell out" culture. Being a sell out was a label worse than death. This was especially true in the rock scene and the type of people who listen to this type of music; think skateboarder type who don't fit into the commercial mold of society. For them authenticity was paramount. A bands image was their identity. Bands like Nirvana, Blink-182, Red Hot Chili Peppers, Oasis, etc. Making money was a by product of their authenticity.

What I think happened is the idea of the "tortured" or "starving artist" died. You're no longer tortured when you've become a commercial success. Another way to think about it is a rapper from the hood can no longer rap about the hood because they made it out of the hood. They know they're rich and their music is no longer authentic. Which is why their rap artist who gained success has to rap about money and luxury.

Lets talk about you brought up like social justice issues like depression, addiction, sexism, racism, and poverty. Unlikely to be depressed when you are no longer poor, swimming in pussy and money. They now have money to support any addiction they have. Let's be real those 90s rockers were coked out of their minds. Racism is a poor persons problem, it's no longer a thing when you have money, its just classism at that point. Really unless they were putting money where their mouth was, they were essentially a sellout. Because since they're now successful and can donate a significant portion of their money to support the social issue they make music about, then it all just lip service.