I learned it as a teenager and I’m far from a big talmid chochom…anyway, we’re not just talking about everyday Americans here. If it was a real halacha, the rebbeim could get together and make a kol koreh. Why didn’t they?
Principle, not principal, and you should clarify what you mean by “public exposure” and “being on the streets”, because that may have to do with the actual nature of the errand, not just stam being out of the house.