I always feel sorry whenever I hear about anyone who is lonely. We have all experienced it, sometimes for extended periods. Reading that an entire generation or two might be more likely to feel lonely is discouraging.
I am always suspicious of statistics about entire age-groups. Not only are the boundary lines fuzzy, but they always involve trends and percentages, not either-ors. If Boomers check some box 40% of the time and it steadily lessens until Gen Z only checks it 25% of the time, that may be significant and worth looking at, But it means you shouldn't be drawing a conclusion about any individual you are meeting fresh, nor even about the generation as a whole. Some key word in the question might have a different meaning. The difference may reflect their current age more than their generation. That is, those same Gen Z'ers might also check that box 40% of the time forty years from now.
I found it interesting that "transparency" was considered an important value. That word would not have been used in a survey forty years ago, and "authenticity," which I suspect is related, would have been less likely as well. Do they mean "candor?" Are they used here as opposite words to what people are really thinking, signifying "not a fake, not a hypocrite?" Both could also serve as excuses for people who want to tell others off, or do whatever they want and not be criticised, like the NBA player who said he was a Christian because "No one but God can judge me." Is openly being a jerk transparency or authenticity?
The article ties it to social media, and few of us doubt that has some effects on personality at this point. At my son's 40th birthday party I was admiring my brother across the room, watching him talk to others, just enjoying that before going over to greet him. I mentioned softly to another son how much I enjoyed "just watching him." He mentioned after a minute or so that I could not have said that five years ago. It's true, and part of that has been going off Facebook, so I don't see his comments anymore. We can get over things that annoy us more easily when new annoyances are not added to them. Decades ago a friend shook his head when talking about difficulties with a tenant, "It's easier to forgive people if they stop sinning against you."
Are the effects permanent? Once they are part of our development, are we changed forever?The internet in general has made discourse less formal. Blogging and personal websites have increased the number of people sharing their opinions to a group. I was 52 when I started blogging, already well into middle-age, and had commented and participated on other sites before that. I find differences in myself related to frequent expression of my opinions and interests since that time. I can't be the only one, and it is hard to see how such self-expression would have less effect on those a generation or two younger. We guess at what the changes are among those who grew up with their own camera phones in their hand, but I don't think there is much solid evidence yet.
Think for a moment about the different lives of the past, of children who grew up on the prairie, or in a London slum, or in a peasant village. Those are hard enough to get our heads around, never mind the remoter lives of hunter-gatherers, nomads, or slaves. Some of those had constant human interaction, some had very little.