> The main goal of business is to generate the most income with the least expense

That's the goal of small business. It is the only way to stay afloat and try to grow while allowing the stakeholders enough to survive. Large business starts to generate so much income that it could never possibly spend it all anyway, so minimizing expenses doesn't really matter. What does matter, to the people running the show, is ensuring that they gain social status.

And for that you need visibility and connections. The way you get connections and visibility is to build impressive offices and fill them with notable people. The work might be technically pointless, but it generates a network of friends in high places and that is what provides social status. A trillion dollar business that is one guy in his parents' basement might sound appealing to the average software developer, but not to those who actually run these large companies.