So those musicians are no longer getting booked for that bit of music. Instead, one person produces it in their home studio. But, there’s now an industry for creating software tools that support that workflow, and there are a lot more opportunities for such music than there used to be. The amount of music used in background spots on television is astounding.
Things changed. Some jobs diminished (studio players?) or went away altogether (music copyists?). But new work came into existence.