I think this is the main thing most music fans (and young musicians) are forgetting: historically, musicians have never made money off of album sales, labels have. Musicians make the bulk of their money from touring and merchandise.
Steve Albini does a good job of breaking it down here: https://thebaffler.com/salvos/the-problem-with-music.
FTFA:
> For the average band, a $250,000 advance (in 1993 dollars) is distributed like this:
> Record company: $710,000
> Producer: $90,000
> Manager: $51,000
> Studio: $52,500
> Previous label: $50,000
> Agent: $7,500
> Lawyer: $12,000
> Band member net income each: $4,031.25