Yeah, about that: In most jurisdictions copyright lasts until 70 years after death. So that means in 2026 that both composer and all performers must have died before 1956. Using such old songs from old recordings is simply not feasible for most companies.
There are also good reasons for people to use AI music. If you just want some music as background in a video you want to post somewhere, that totally is a legal nightmare here where I live. If you’re some small business, that is even more nightmarish. Licensing songs is expensive and hard to do, so just generating some ok tune is the best way forward
And what is the fundamental difference between the background music styled songs from the YT Audio Library that were done for a small penny in a short time by some underpaid performer vs. something a computer created?