> If you look at somewhere like London, then pretty much every busy intersection, every public square, every station, every bus, every train, etc has CCTV.

My experience as a londoner is that privately or quasiprivately operated spaces (including trains and buses) and roads do but public spaces like squares or parks don't. When I was mugged in a plaza there was no public CCTV coverage but the police requested CCTV footage from a private gym bordering the plaza. I think that's pretty normal for london.