Do you have an example of anyone who built a 100B company who actually had that as a goal ?
Microsoft's old mission statement: (Paraphrase) To put a computer on every desk and in every home.
Amazon's mission statement: "...build a place where people can come to find and discover anything they might want to buy online"
These mission statements don't specifically state they want to build a $100B company, but it seems pretty obvious that a company that does the things in their mission statement would be worth $100B.