I feel like the proliferation of cheap and loud bluetooth speakers has contributed to the scourge of noise pollution significantly in the last two years. The parks are filled with them. People also seem to walk and bike around cities confident that everyone around them really wants to hear their music above all else. It's a truly bizarre and recent-ish phenomenon, and it's full-grown adults. I'm guessing the prices maybe hit a tipping point or the personal public soundtrack is now a statement? I'm at a loss for how to explain it.