irrelevant. Only 1 billion people can have it and 7 billion want it.

It is relevant. Imagine everyone wants to use a car. Is everyone going to be using a car at every point during the day? No.

Shared ownership allows you to drastically reduce the number of items that need to be produced. Look around you at the things in your house. How many of those things do you use on a regular basis, and how many things are under utilised for most of the time. Shared ownership means you get access to a much wider range of items whilst reducing the cost of ownership.