Apple also has a nice statistics of >>all used apps on Macs<< since 2017 - every app start is reported back to apple. One could see from such stat what is being used more, what is being used less and then make business decisions... Maybe somebody will sue in the future...
It actually depends on if this data is maintained at an individual level and is personally identifiable. This data is almost certainly deidentified in Apple's case, which would make GDPR not applicable.
