Older folks criticize Millennials without realizing younger people don't have the advantages older people grew up with. Like two parents, let alone an extended family. Like a church or other spiritual community. Like clubs, hobbies, and the time to have those things. Like a reliable job or benefits. Like childhood friends, neighbors, and other long-term relationships. Like downtime.
People are more mobile, more isolated, less physically and mentally healthy, less secure, and more exhausted. Because duh, when you hack away the support system and surround people with a constant barrage of noise and demand, they will break down. And it's not their fault, they are not weak or lazy, you have just built a shitty society that breaks people.