I expect that when someone implements a subtask or a single user story will only require changing few components. Sometimes the commit can have up to 60 files changed.
Note: I don't think my question is a duplication of I changed one method signature and now have over 25,000 errors. What now? In my case, I am trying to understand if the software suffers from high coupling or not by looking at the cost of code review. Why changing the behavior of a user story requires many changes in the source code?