I usually avoid strangers, because those who talk to you are usually weirdos. Thing is, if normal people don't talk to strangers anymore, then only the weirdos are left, reinforcing the idea that only weirdos talk to strangers...
+1 In any major city it's probably 90% chance they're either a crook trying to scam you out of something or mentally not quite right. The remaining 10% will be tourists or people from outside of the major city.
Nobody wants randos coming up to them and asking for something.
Most people would be less lonely if everyone had more practice at making non-transactional conversation.
Actively avoiding conversation still qualifies as "weirdo" behavior to most people.