Hello!
Yes indeed, they are, and cases from websites are great -but a limited resource, unfortunately, since they are little-.
This said, it´s very different to have it written than making it as a life interaction with someone, and furthermore doing so in a high-stress situation as the interview is.
Have you seen the cases here in PrepL library? Particularly if you focus on the coach ones, that are recent, you will find representative cases made by people who are totally in touch with the interview world on a daily basis.
Hope it helps!
Cheers,
Clara