How common is this, in your experience?
Would you worry about your son or daughter if they entered adulthood without any friends or a social circle?
I know people like this, who are well educated, work full time in professional roles with decent pay and who are “normal” in every other sense. But they have spent their twenties and now their early thirties alone. They’ve never had a holiday with friends, never have plans to meet up with anyone for a drink or go out with and are always single. Never been invited to a wedding or a party and generally do everything alone.
Would you be concerned about the future for someone like this? Or is it much more common than people would believe?