But if we're on the topic of creatives, just look at the pushback that the Jackson 5 received in America or that NWA had in the '90s. Yes it probably was easier to be a white, male artist in the '50s-'90s (like the Beatles), but the case was much murkier for anyone else. And it's not like the establishment went unscathed by technology change either. There's a song titled "Video Killed the Radio Star" after all...
Yes, minority artists might not have made it big in the past, but there was demand in the establishments that were run/supported/patronized by their respective group.
If anything, technology has made success/wealth inequity worse by making music cheap and accessible, thus allowing people to have unlimited music (replays) for little money. This killed a lot of live music and funneled that money to the upper echelon on musicians.
Further improvements in portable audio like the cassette tape, the CD, and eventually digital music only improved the portability of music for individuals but commercial settings have had the ability to replace live music at venues for a century. I don't think the root cause for the decline of live music was technical. I think cultural attitudes toward music changed, that's all.
I do see cultural attitudes playing a role too. My guess is they both play a part.
An abundance of wealth and entertainment. A record number of people are able to eek out a minimal living without having to work in traditional markets. It is not a great life, but not desperate enough to enter the job market.