From a comment a couple days ago a poster claims we all need to be equal in creative control when we sit at the table.
While i agree an improv can be very entertaining. They dont have staying power. A world where for arugement we will say 5 people all have equal creative control is going to suck. It will be a patchwork mish mash of 5 minds. I like my game worlds to at least appear internaly consistant.
If your creative desires are so great, become a DM! Write a book/story/novel. Paint or draw. But come to a DMs world and try to creatively change what has been made. That is the hallmark of a bad player.
The world we DMs make is you players to explore and interact with. Not for you to edit as you wish.
The more i look at/interact with the story as play types the less i think any system can unify fantasy role play.
WotC is in way over its head.