The real issue, I think, is social media combined with the nature many millenials were raised around.That's really just sad. Mental illness, especially depression, does lead to an inability to cope with basic everyday necessities, but 7 out of 10 saying this is way too high and reflects more on how they were raised than anything. Personally, I guarantee that either the article is overblowing this or the methodology is flawed, because men saying that simply eating healthy is their biggest stressor doesn't quite make sense if someone believes every part of themselves isn't good enough.
Millennials were the "participation" generation, and were told that they could all be special. Everyone was capable of great things. Everyone is a winner. Everyone can be good at everything. Laws like no child left behind were passed to ensure that children simply could not be allowed to fail. Educational institutions coddle these children, well into college age, creating this social bubble where consequences are meaningless. Not only does this breed entitled shithead behavior, but for the good kids they never learn how to deal with failure, pressure, and unfair situations.
Then throw in the internet. Social media creates a faux reality. Everyone seems perfect, their lives seem great, and your life, by comparison, seems shitty. Social media use is linked with feelings of depression for good reason. Everyone ends up in this constant "keeping up with the Jones'" not only with material goods but also with actions. This is thrown in with the overflow of information that the internet provides about every subject you can imagine. So if you are not maintaining a proper diet, driving a nice car, living in a nice place, with the latest games, great parties, tons of friends, taking fancy vacations, and working a great job while staying in shape and volunteering ece. all at the same time, you mentally associate yourself with failure because your primate brain sees the curtailed life presented by social media and says "you are failing". This can lead to something as innocuous as eating right or going to the gym being seen as a major failing of one's character.
This is coupled with millennial's crippling social skills, largely resulting from decades of coddling, living in bubbles, and the censorship and echo chambers social media provide, results in so many millennials feeling very negatively about themselves. They are trapped in a vicious cycle of self loathing and helplessness. "just stop using social media" the peanut gallery chants. Well, if you are in this position, that seems incredibly daunting. Many in that age group, as well as zoomers, prefer to use social media for most communication, and if you talk about leaving, many will give you a hard time about communicating with you over email, text, and even phone calls. The task of rebuilding your social life, for these people, is a daunting task they have no idea how to tackle. and they lack the developed skills Gen X and boomers had at that age to create new friendships and social groups.