It's probably quite difficult to boil it down to something as simple as an "off" switch that'll limit costs for them, meaningfully work for all services, not be

It's probably quite difficult to boil it down to something as simple as an "off" switch that'll limit costs for them, meaningfully work for all services, not be abused, not be confusing, and not result in the customers that actually make you money accidentally getting important things shut off unexpectedly under predictable circumstances. It's probably easier to make it so they can set up alerts and have a human on their end evaluate what steps are worth taking to cut costs while maintaining important availability.