People are bombarded with politics all day long on social media, the news, and late-night TV. Perhaps they don’t want it in their music also.
Plus, music is no longer a major player in entertainment or social movements like it was in the 60s and 70s. For many people, music is background noise to study or exercise or jog to. Most working musicians are struggling to make money. Writing protest songs is not going to help them with that goal.
Superstar musicans can “protest” on Twitter, Facebook, Instagram, etc. anytime. So why bother with protest songs?