A career as a performing musician was reliably lucrative for a brief moment in time, maybe the last 50 to 75 years. Before that, musicians were artists, more or less monks to their trade.
Appears it’s headed that way again. The systemic reason, as Townsend points out, is that the human and performance space infrastructure for live music have degraded and the costs to tour have soared, creating a terrible situation for the not-super-famous touring act.
For the regional and local pros, there’s the competition of cheaper and more convenient entertainment options these days as has been discussed here thoroughly.
The last factor, affecting fewer but still worth mentioning, is the choke hold the promoters have on the high end of the live music business. For example, I do not think Taylor Swift expected or wanted the situation that Ticketmaster created for her upcoming tour. Whether you like her music or not, she realizes that millions of her fans can’t come to her shows and it’s largely due to a money grab by the non-artistic part of the business she’s in.
I don’t have a solution.