I’d say mostly for validations and verifications.

For example

In Lead, I want to know whether someone’s SSN name is the same with their tax ID name. In my country, those two can be a little bit different. If its too different, I want to follow up the lead automatically

And also in flow, you want to check whether the new value of a field, is too different or not, if its not too different you dont want them to update the value.

Thanks for the great question!