The mainstream doesn't really exist like it did in the '70s and everyone is in a little niche. And even if you do want to talk about mainstream it's pop and hip hop, where the are some really great artists making some cool stuff, lots of amazing arrangements and sound design.

The world has changed and people are often just more interested in social media and games than music. It'll never go back to the 70's and 80's and we just need to accept that and play the hand as given. Imagine how it was for the Jazz Big Bands when rock arrived.

Interestingly only in prog can a new artist be from the 90s!!
Have a great day X