My uneducated guess would be that, overall internet speeds have increased enough that streaming is feasible for most people and that there is a lot of healthy competition in music streaming, where almost all of the major competitors have nearly identical libraries, so you don't need to pay 10 different subscriptions for music.

Additionally, there exists services like tidal which offer lossless streaming so even the hardcore people can get all (most) of their music legitimately.

Basically the music industry did the opposite of the movie/tv industry and generally figured out streaming a long time ago.