Which can also be used intentionally as a feature.
It's common from users to expect that when given an exact number for progress (35%) that percentages are themselves exact and evenly distributed. How many people hear bug reports that it took extra time to move from 36% to 37% than from 35% to 36%, or were worried that the system might have been stuck or crashed at 54% because it took so long, from someone trying to eagle eye your progress indicator?
Just because you can give a progress percentage doesn't mean that the user needs to know the exact value of that percentage or be able to visually compare progress indicators as strongly as possible.
It's common from users to expect that when given an exact number for progress (35%) that percentages are themselves exact and evenly distributed. How many people hear bug reports that it took extra time to move from 36% to 37% than from 35% to 36%, or were worried that the system might have been stuck or crashed at 54% because it took so long, from someone trying to eagle eye your progress indicator?
Just because you can give a progress percentage doesn't mean that the user needs to know the exact value of that percentage or be able to visually compare progress indicators as strongly as possible.