Marketplace

This may be a stupid idea or a brilliant one. I thought of this since playing Factorio.
What if there was a marketplace where players could sell what they produce and others would buy those resources rather than building the whole infrastructure.
Imagine having a pipeline at the edge of the map from where you could connect your stuff and build from there, the way countries operate (I'm thinking of that damn russian gas pipe).
So people would have to run the game (or host a server) that generates these resources and then choose if they want to sell it and for how much. And the people buying the resources wouldn't have to start from scratch if they want to start a new game, they would have to build the same stuff over and over again, as long as they can afford those resources of course.
But then this begs the question, what would be the point of the game anymore? I dunno, what's the point now, sorry, I haven't played it, only played factorio.
What do you think? Stupid or brilliant?