I think it depends on how you define that. People were quite happy with HMM-based MIDI generators that could generate Beethoven- or Mozart-like sequences 10, m

I think it depends on how you define that. People were quite happy with HMM-based MIDI generators that could generate Beethoven- or Mozart-like sequences 10, maybe even 15 or 20 years ago. But of course other people pointed out the problems of it being boring eventually. Then LSTMs improved long-term dependencies and people were impressed by the improved quality of generating whole musical pieces. But still others thought it was not good enough. Then the goalposts moved again with transformers and neural vocoders and now we want top-40 direct audio generation. And these latest systems can kind of sort of do it! But still there are people who demand better. And so on, things will continue to improve. Progress only moves as fast as expectations, and expectations move with technology. Music is not special in this respect. So you could say at any given time in the past that some people "see meaningfully high quality" and others are disappointed. You see exactly both these sides of the spectrum even now with text-to-image and text-to-audio technology.