Ideas number 3 and 4 together sound to me like the foundations of a generalised "intent economy": a buyer expresses what they want, and the platform dynamically

Ideas number 3 and 4 together sound to me like the foundations of a generalised "intent economy": a buyer expresses what they want, and the platform dynamically builds the graph of agents required to fulfill that intent, including quotes, bidding, idea/pitch refinement etc. as necessary. Maybe you just want a burger. Maybe you want a gift for Mother's Day but you have no idea what. Maybe you want a new house designed and built. I don't think I actually _want_ this (I view Uber-for-everthing as kinda dystopian) but I'm amazed that nobody has made a serious attempt to build this. Uber has one part of the puzzle in their driver-customer connection and order fulfillment platform. Facebook has another in its social graph. Amazon has another in its marketplace and Mechanical Turk. And a thousand other companies have one highly specialised subset of this, like finding and scheduling a couple of tradespeople required to do a job on your home. I must be missing something that makes it a lot harder than it seems, or that means there's a lot less value there than it looks like on the surface, because why else have none of these huge players decided to go for it?