Ikagura
Mini-Boss
I really think that many in the last generations lack discipline (and since parents that never grew with any won't apply it to their own kids).Honestly, I believe the most important thing is an understanding of discipline.
Discipline can come in many forms, such as sport, dance (especially ballet), music (especially classical), etc etc. But the main thing is whatever discipline you learn, you will grow to understand that defeats = lessons which make you stronger.
Your persistence in the face of things which seem impossible, your overcoming of frustrations and defeats, your acceptance of training from people who know more than you (even when they criticize you) will ultimately result in you having strong mental fortitude. A vital component of "growing up".
And also it will result in a skill that will help you through your life journey.
Parents who truly understand this will raise strong children.
Not to say we should bring back physical punishment (I'd be absolutely against that because it can lead to issues later in life) I think it's never a bad thing to "correct" a kid that does not understand boundaries nor making efforts with discipline (like removing access to screens, forcing them to write an apology letter or even public apologies in front of the person they may have hurt with the presence of more than one witness).
And stop telling to kids that "they're unique" or "special" because they would think they don't have to make any efforts.