I'd also argue that class differences - and the innate conservatism of the music industry itself, - have helped to 'kill' rock music. While there good bands exist today, they don't define a generations's sense of self the way music did 30 or 40 years ago..
I think you could argue that it was technology rather than any specific social change that changed the position rock n' roll music held in society.
What we think of as classic Rock n Roll's dominance coincided almost exactly with the dominance of one particular mass-market music distribution mechanism: The
stereo 33⅓ RPM long playing vinyl record album.The "LP". Which ran from roughly 1960 - through 1985. And I'd argue that it was the rise of this particular technology that helped create the great bands of that era. It contributed in some ways to the breakup of many of those bands. And its passing as the dominant sales and revenue stream ushered in not only new artists, but a new type of popular music.
Before the Long Playing album; most bands created their new material one or two tracks at a time. A "hit" for side A of the single, and a lesser work, or a cover of someone else's song for the B side. A group could go into the studio one day, get the song on tape after a few dozen takes, and be out on the road again in a couple of days. Their studio time was limited. Musicians would come up with new ideas in hotel rooms, during jam sessions, and show up with the bones of a song already pretty well established.
You couldn't do that and fill an entire LP. For which you need any where from ten to fourteen separate tracks. And you generally can't make half of those "covers." Going into a studio meant, for many bands,
months of more-or-less monastical labor, often toiling under the direction of a producer highly trained in both the art and science of music composition and recording. It was this process, working intimately with band members, collaborating with the producers, experimenting and arguing, that gave us classic Rock. And it gave us the concept of an
album. A musical composition that was supposed to be greater than the sum of its parts. Not least because people generally listened to (at least) one side of each disc at a time.
I would also note that the social strains of working cheek-by-jowl with bandmates ultimately led to the break-up of all but a handful of the greats of that era.
That all started changing in the early 1980s with the Compact Disc. For one thing, consumers didn't have to listen to songs in the order they were laid down on the album. And so the role of the album as a whole as a musical composition began to wane. Resulting in a return to the "hit" business model. And this process has only accelerated with the introduction of devices such as iTunes and iPod and (now) streaming models of music distribution.
Lastly I'd argue that computer technology has significantly lowered the barriers to entry for recording music. Any kid with a laptop and open-source software nowadays has access to techniques and effects that would have stunned George Martin back in that Abbey Road recording studio. Whether they really know what to do with those effects or not is another thing entirely.
Musically at least, technology both giveth and taketh away.