Because it's so far divorced from reality people lose all sense of identity and purpose. Our prehistoric ancestors worked less hours than we do and their work was more rewarding, and they were more in touch with nature. You don't have to be a hippie to see how urban environments are dehumanizing and spirit-crushing.
People today, especially white people and Asians, are raised in a very rigid system with all the wrong ideas. Not only is the public education system designed to wear you down into another replaceable worker/consumer/soldier, but modern progressive ideals are teaching boys to act like girls, and vice versa. This is obviously bad for their mental health.
This double indoctrination doesn't end when school does, either. Kids are told they'll never succeed unless they take on a shitload of debt and go to college, and almost all colleges today are liberal shitholes, more focused on facts than feelings. Some are better than others, but almost all are like that. They're shamed for opting out and going to trade school for a blue collar job, even though those kids will likely do better than the college ones. And there's also a social stigma associated with the drastically cheaper community colleges. Then with the sexual revolution, "alphas" and "betas" are even more separate than they used to be. In a culture than encourages promiscuity and idolizes whores, college girls give it up freely to the top 10-20% of men while the rest remain alone, taking the scraps. This isn't healthy for men, women, or society. It's natural of course for the most attractive men to have most of the sex, but it's more exaggerated and celebrated now than ever.
And when they're done with that, they're off to the workforce. Some lucky few will find jobs they enjoy, and good for them. Some will start their own businesses, even better. But most of em will either find shitty jobs, or no jobs at all. The people with the shitty jobs will have their entire life defined by their work. And with all the debt their degree cost, they don't have much a choice but to keep to the grind. Never getting enough sleep, spending too much time in traffic, eating shitty and unhealthy foods and devoid of meaningful social bonds, it's no wonder they end up in rough shape. And then of course, you have the poor bastards that took on shitloads of debt but can't get hired, or end up working fast food or retail that pays shit. Society will scorn them, debt collectors will be merciless, and there will be little hope for things getting better anytime soon.
The typical modern lifestyle is fucking poison. Some people make it work, with money, connections, or intelligence. But the average person gets sucked dry, and then they die. The modern lifestyle designed around consumerist culture, which is by its nature soulless and depressing, teaching people that happiness comes from possessions.
It can't go on like this.