It's funny. It's like the interview process is designed to build bad habits. If somebody needs to troubleshoot, I'd prefer someone who reads manpages. If you need an actual algorithm for something, I'd prefer someone who has a look around for libraries first and if it's really necessary, cracks a fucking book and figures out what the right answer is, rather than over-confidently pulling utter bullshit out of their ass on the fly.
Honestly though, annoying interviews are just no-poach 2.0. It's a form of wage suppression if you really think about it.
Obviously the person has to have a clue what they are doing. But I would never expect them to have the details memorized. "I'd look at the docs and stack overflow" is a valid answer. As long as they had the thought process established of what was being accomplished. They knew where they were going, they worked out a reasonable solution but maybe didn't remember some command flag. Memorization is useless. How does the person aproach and solve the problem is far more important.
The harder it is to change jobs or explore opportunities in parallel, the less employers have to compete.
There was a whole lawsuit about no-poach where a group of employers chose explicitly not to compete by agreeing to not hire each other's employees. I believe the same effect can be had by simply adding friction to the structure of the market itself.
What's amusing to me is the brilliance of it. It essentially exploits egos in the workforce to suppress their own wages.
Honestly though, annoying interviews are just no-poach 2.0. It's a form of wage suppression if you really think about it.