It is obvious to me that the solutions you propose would provide a dangerous band-aide to cover over a question that must be addressed personally. Depression would still be an issue - even if all children were lovingly parented, even if there were no 'jerks' in the workplace, or if bullies were eliminated from our schools. Depression is not here to be gotten rid of.
Depression is here to be appreciated.
As a species, we tend to resist both the serious and silly aspects of ourselves. We end up existing in a 'gray muddle' that is truly excruciating to anyone willing to pay even the slightest attention to one's state of being. Depression is the doorway into the serious aspect of who we are. It begins with gravity. Ideally, our homes, schools and places of work would be environments that would nurture a personal exploration of both the serious and silly.