‘Not too long ago, it was perfectly fine for people to turn up at your house unannounced, to pay you a visit, for no reason in particular other than to engage socially and you were expected to host them at your house (!).’

Two thoughts come to mind. First, the effort required for somebody to turn up at your house ensures that this would happen much less frequently than the relatively costless telephone call. Second, some folk probably hate phone calls more than in-person conversations.