All the time on everything. That's how a sustaining economy works. Every one gets a piece by inserting themselves in the pie.

But the same time the idea is that everyone in the chain is delivering value or else they wouldn't be there because someone else will provide something better by ruthlessly removing said intermediary out when it is no longer efficient.

If you have a better way of selling houses between people without the need for that 9-12% you would be doing it now or you would have done it by now.

Literally the definition of a founder. You find opportunities to exploit.