We used to listen to music as a group - a few like minded folks sitting around and playing records. It's how we found new music and got tuned into what was going on in the world.
There are too many other things to do now other than just sit and listen to tunes. The Internet and social media eat a bunch of time that we'd have spent listening.
The ways we get music are different now, too. Instead of everyone hearing the same radio stations (even the underground FM stations) music is streamed to everyone individually. Back in the day the protest songs could be played on the underground FM stations and reach a lot of people. Now you'd have to figure out a way to attract like thinking folks to your stream/podcast before getting enough ears.
The style of protest music has also changed. Back in the Vietnam era it was folk music. It takes different forms now and the other styles of music aren't necessarily what older folks (like me) are going to hear.