They _kind of_ have this, within the limits and goals of Minecraft. They've spoken recently about one of their intentions for Survival is for the world to be a

They _kind of_ have this, within the limits and goals of Minecraft. They've spoken recently about one of their intentions for Survival is for the world to be a blank slate for players own creations. Adding more and richer structures detracts from that. There's also the part where it's still a game that needs balancing, and just importing arbitrary structures and resources detracts from Survival. There is the marketplace which has community servers/worlds/levels that showcase what other people have built. I think that's the right level for this. Otherwise, stuff like this is perfect for the data pack ecosystem they created.