The music market is likely goint to converge to the following two extreme segments: A) audiences who are mostly interested in idols and lifestyles, where music is merely a means to an end, and B) audiences which are mostly interested in the music itself (either as main act or in the background). For the A) audience, music is actually secondary and more of a supporting function. For the B) audience, the musicians or composers are secondary (i.e. mostly relevant as a source reference for getting more music). Since serivces like Suno have reached an excellent quality level for most genres, it opens rationalization potential for both groups of audiences. The production companies who focus on the A) audience can massively reduce their production costs (i.e. instead of a "ghost composer" and behind-the-scenes musicians they just use generated music); the only obstacle
for them to overcome are today's copyright laws which don't protect computer generated music (which I personally still prefer to state-imposed monopolies enabled by patent or copyright law). The audience B) instead has access to an inexhaustible supply of new music that interests them, without having to wait for new releases.
Whether people will still learn an instrument or become musicians is a question that is difficult to answer today. The decline of this profession actually began with the invention of recording technology and has steadily increased since then. It is now almost impossible to make a living from it, and that was already the case before Suno and co. Services such as Spotify have taken anonymization and commodification to the extreme. Nevertheless, people still learn instruments and make music. It may well be that the creative possibilities offered by services such as Suno will even inspire people to make more music again.