Maybe it's since lockdown. Maybe it's because it's cheaper to party at home rather than go out.
Playing music in the garden used to mean Alexa or a small Bluetooth speaker etc. Yes it might annoy your immediately neighbours but the next street couldn't hear it.
When did it become mammoth speakers and DJ style turntables?! That can be heard three streets away?
It's a bit like deciding to run a bar from your home.