This is part of the problem for sure, but it's also how the revenue is split between back catalog vs new music.
In the physical media era, when you bought a record/CD you owned it forever and your marginal cost of listening to a song approached zero over time. Most dollars went to new music.
Now, it's close to a 75/25 split of dollars going to back catalog vs new music on streaming services.
If you're a new musician, you're not competing against new music, you're competing against the entire history of recorded music. You're fighting for a piece of a pie that the Beatles are still taking a chunk of.
And the labels are a part of the problem there, they made the deals with the streaming services that allows back catalog to dominate.