I don't even think the issue is custom exhausts or revving engines honestly, because it seems many stock motorbikes have incredibly loud exhausts already. Certainly loud enough to drown out speech. Yet no one seems to care. If I'm walking down the road having a conservation with someone then a noisy motorbike goes past people don't seem to react to the motorbike, instead they just instinctively start shouting at me so I can hear them over the bike as if that's a perfectly normal thing to do.
Same thing seems to happen when I go into shops and restaurants these days. I feel like I'm going into a club or something, yet no one seems to notice until I point it out. The music is always so loud that people are literally shouting over the noise, yet no one thinks this weird. In fact they think I'm weird because I can't handle the noise in these kinds of places.
I get I'm an outlier here, but I've always been amused by that. It seems to me people must actually like noise and shouting at each other because obviously no one is forcing anyone to buy really loud cars and bikes, nor is anyone forcing restaurants and shops to play music so loud you can't hear people speak. People seem to actually have a preference for loud exhausts and loud restaurants.