Coddling them through a perpetual adolescence isn’t doing them any favors; it’s setting them up for exactly the kinds of failures you’re referring to.
Should a kid spend a summer during high school working a "regular" job so as to understand what bullshit average people have to go through (and to do everything possible not to end up in such circumstances)? Sure. Why not? It's a useful experience, when you're 17, to see what life is like for most people.
On the other hand, Game Theory 101 tells us that forced plays are often lousy moves, and that having more options entails higher expectancy. If your kid, as an adult, has to work crappy jobs that damage his career, while others get to make choices that enable them to have better futures because they aren't worried about month-to-month bullshit, then he's going to end up losing through no fault of his own... and, see, this is commonplace. We aren't actually smarter than the poors (the real poors, not non-billionaire "poors"). We just ended up getting dealt better options, whereas they had to operate constantly under constraint.
If you can take stupid obstacles out of your child's life, you should.
I think this falls into the category of "In theory, theory and practice are the same. In practice, they are not." Teaching children, in an age appropriate way that takes their unique strengths and weaknesses into consideration, is the definition of parenting. Preparing kids for life on their own is important.
Keeping commitments, budgeting and long-term planning are important skills. Having someone pay a small amount of rent is a reasonable way to do that. Not the only way, but it's a viable way.
In today's world, I don't think you should have kids unless you have enough wealth to guarantee that they won't have to rely on the labor market to survive. That doesn't mean you need to have enough money for them to live like private jet assholes; but you should be able to leave them enough that they can do what they want with their lives, because the era of "good jobs" seems to be ending.
Unfortunately, I don't think there's any way to prepare children for the life that lies ahead for them. There are too many unknown variables. Within 10-15 years, we're either going to have a complete (and possibly quite violent, thus unpredictable) global overthrow of capitalism--this is necessary, but there's no guarantee of what comes afterward being better--or we will see the opening steps of regression into such a degraded state--techno-capitalist feudalism within a collapsing ecosystem (in Fraser's terminology, a rentism that turns into exterminism upon pressure)--that will leave humanity unlikely, within anyone's lifetime, to recover.
1950s parents prepared their kids for one world; in the 1980s, their kids entered one that was slightly shittier (economically speaking) but still fairly similar. Most of our (1980s and '90s) parents prepared us for a world that no longer exists; we ended up coming of age into an unrecognizable country. (Who would have predicted, in late 1990s, that working conditions and living standards in the US would be third world within a generation? No one; I remember; I was there.) I feel really bad for parents today, because there is no way of knowing what the future is going to look like, but the probability of it being absolutely atrocious is much, much higher than it should be.
I think there's several sects of religion which disagree with you. IE Catholic Lent, the entire amish religion, monks of any kind..
I'm also curious what your take on chores and allowance is then as well?
I think children should do enough chores to have a sense of self-efficacy. Same with survival skills. Being college-age or older and not knowing how to cook or do basic cleaning is an embarrassment, even if you're rich.
All that said, if you want your kids to succeed in the world, they have to know how to do a task without becoming the one who does the task, if you catch the distinction. In the workplace, you have to be willing to do unpleasant jobs, but be extremely selective in what you're willing to let yourself become the one who does. Outside of the upper class, no one really learns this skill. People from working- or middle-class backgrounds are either too resistant to doing tasks they consider beneath them (which is a bad look) or too willing, which leads to recurring time and image costs that eat up their ability to have a career.
Except for those of my contemporaries--boomers--who were lawyers and engineers, most of us were not that prosperous in our twenties, I think.