Why would the exchanges want to move their colos into the cloud. They've spent the capex and they can charge lots of money to rent data center space, cross con

Why would the exchanges want to move their colos into the cloud. They've spent the capex and they can charge lots of money to rent data center space, cross connects and other services to their customers. If they moved to the cloud, all that revenue would go from them to AWS/GCP/etc. Doesn't seem like a profitable move for the exchanges. They make more $$$ with on prem setups.