I wouldn't call out the depression bit as a Gen Z exclusive. Millennials basically invented modern, every day, gallows humor. Arguably, they're also the ones to normalize going to therapy. Not to say that things aren't bad, just saying that part didn't start with Gen Z.
Older people think younger people are stupid and reckless, and viceversa. And the younglings think they "figured it out" like no one before them. But no one ever tried to understand each other in the process. Rinse and repeat.