What you are saying might be problematic. This is a naive approach towards saving cost in the cloud. Companies who would pay big bucks for a platform like this, I would imagine they would optimize cost by managing commitments on Reserved Instance over 1 year/3 year or sometimes monthly via platforms like some non-aws platforms. Net-saving is much higher than just turning off/on instances.

Managing cost without impacting any infrastructure is the right way to do it in my opinion.