As per modern researches, children gain self-control by age 8 (Some gain it early. Some gain it late). Ability to say conscious ‘No’. Ability to decide between most favorable choice and least favorable option. This is just a beginning. Mother Nature has put seeds of self-control at this age. It is society’s responsibility to nurture this human value so that child become ideal Grihasth.
As per followups of famous “Stanford marshmallow experiment” of 1970s, children who could who delayed gratification longer in the self-imposed delay paradigm were more competent in life. They had successful Grihasthi life.
In this experiment, there was no special training given to children. Our culture believes in empowering everyone. So, Gurukul for everyone, as per their needs and capabilities.
One critical factor of Gurukul system is Brahmcharya i.e. Self-control over mind and body. Those who ridicule it are either dumbest of all species or full of ignorance.
Do not play with your child’s future due to your whims and fancies. Your biases. Without teaching self-control, there is no bright future, materially as well as spiritually.
At least, do not ridicule your culture. At least respect if you cannot follow.