It is, but generally reasonableness comes with useful legal context to help you understand what it means.
In the context of GDPR? I was left guessing what a regulator in Brussels might consider reasonable when their path to career advancement might run through my employer. Coupled with being uncertain what various national regulators (or empowered industry bodies) might add in, as they were allowed to do so until quite literally the last second. It left a person with no good way of judging what might be considered reasonable, only nervous paranoia.
It was a distinctly unpleasant experience and one I was left thinking was both anticipated and avoidable.
