I am sure there is some protest music out there but it is a few drops in the ocean of musical content. I also think music is no longer the major form of entertainment or voice of social justice is was pre-internet. It now has to compete with social media, Netflix, YouTube, etc. And on social media you can instantly express your disgust for government. No songwriting required. With politics saturating every medium, and most musicians struggling to make a living, protest song are probably not a priority. And a bit redundant.
Who isn’t sick of reading political rants on Facebook? Maybe people want to use music to escape politics now. But don’t worry, late night comedians have taken up the cause.