I am sorry but this is completely false. All artist contracts in the 90s stated the label would pay upfront, but all costs would be recouped from future album sales and touring profits before the artist saw a dime. The labels didnt take a chance on anything, they heavily covered their asses by monumental contracts which were very famously difficult to get out of once signed.
But if, as I suspect, most contracts were structured as advances, then if the musician was successful, you could look at it as the musician just having gotten a loan.
But, famously, most musicians aren't very successful, and they aren't in general asked to pay back their studio time.
So I don't think "completely false" is a reasonable response to "the label paid for studio time".
These days with creative tools so accessible and widespread, and the ability to publish so cheap, artists need to produce their own music and find their own following before the label takes them on. Instead of the label paying for studio time the artist does. I think that's why these discussions concentrate on the whole "fewer artists making more of the share" part. It IS different, but its not the whole story.
And I'd probably argue in favor of making creative endeavors more widespread instead of being in the lap of a few label executive taste-makers, but you definitely have fewer artists who can just concentrate on making great music and getting nice royalties. Now you have to do everything for a smaller pay day.