Reddit is pretty much a case study of upbringing without effective punishment. In real life kids behave because they have skin in the game—if they misbehave, they are not allowed ice cream. On the contrary, if you are banned from reddit, you can simply reset your browser and create a new account. I doubt you can fix reddit with a smarter design, because that won’t change the troublemakers. To fix reddit, you would po…
Upbrining without punishment definitely is definitely possible and practiced semi widely (google around). Punishment is a pretty bad way to address misbehaviour.
As someone who's anticipating having kids in a few years, I'm genuinely curious as to what a better approach is.