I think people often try to emulate policies from large successful companies without necessarily understanding the context for why this policy would make sense

I think people often try to emulate policies from large successful companies without necessarily understanding the context for why this policy would make sense for those particular companies, but not for others. In a company like Google or Facebook, it may not matter whether or not you have any experience with technology X, because they have a large training organization that will teach you proprietary technology Y anyway. Their interview process might therefore come across as overly academic, because there's a good chance you might have to "study" and quickly learn something arbitrary as part of the job. In a much smaller organization, it's unlikely that you will encounter any technology or basic problems that haven't been seen before and it's much more important that you have a baseline level of competence in your expected job. It's also less likely that they have an organization dedicated to training software engineers. Logically, these very different types of companies should have very different interview processes, but that isn't always the case.