Why the hell did sprints ever become a thing? No one can sprint indefinitely. A sprint is a burst of energy. Once the energy bursts, the crash comes next. If we are on a constant cycle
Work should be as consistent as possible, but we understand that it is not always possible. Some work is big and some work is small. Work may need to split out to allow easier review or parallelization. Over time, we get better at figuring out what a unit of work actually is.