If you avoid the slightest possibility of unpleasant and pointless confrontations, then you’re going to lead a very dull life. I sometimes photograph random people. Never has anyone had an issue with that. Sometimes they approach me and we have a chat. That’s all that happens. I’ve had more chances of being hit by a car than anyone having an issue with me taking pictures of them. Boils down not being a dick about it.
When we were travelling in the Andes, we were warned multiple times to not take photographs of local peoples without their permission as they could take offense. Seems like a reasonable position but should the wishes of people in the Andes be respected while those of people in Europe ignored? If so, why?
Is it standard for people in the Andes to take offence at people taking pictures of them? I don’t know, maybe it is, haven’t been there. It is not in Europe.