With the advent of streaming services like Spotify, it’s definitely getting worse, but the market has always been difficult from a strictly performative/sales perspective. I never made any real money from my compositions, but I pulled a decent side income teaching piano back in university.
It reminds me of ex-Soviet chess players. The emigration of so many good grandmaster-level players diluted the market, and unless you were in the absolute upper echelons (like Kramnik, Karpov, or Kasparov), you pretty much had to supplement your income by teaching on the side.