Speaking for myself only, here ...
I did not leave home and expect to enjoy the same standard of living that my parents enjoyed ... and had afforded me as a child. Leaving home and supporting myself on my own labor included a sharp decrease in standard of living ... but my parents raised me well; I had good training and good habits.
The best thing parents can teach their children is to know, love, and serve God.
The next best thing parents can teach their children is how to make good decisions about the things of this world.
You also need to teach your kids how to do the basics of living. Cook, clean, do basic maintenance and repairs on everything, the virtues of showing up and on time and how to say no.
I will not say that time was all fun and games but it taught me a lot.
Now I hear about young people at the university who have no idea how to put gas in their car and I wonder how they will manage to survive.