Put your thinking caps on: what costs more:
Holding ONE large DC/RC in a rented building like the old days, or hosting months of smaller RC’s from late May to September, which means more smaller buildings will need to be built, upgraded, or maintained?
Could it be that they want to give people a greater opportunity to attend a RC if they have to miss for any reason, or that they would rather be as less dependent on third parties as possible?
Its not necessarily a cost savings issue. If I could provide venues independently, I would as much as possible.