This is a proof of concept. It's going to take many more years to get it into a practical form factor for widespread adoption. In the meantime, early adopters including developers will define it. It's basically the same as the Macintosh. That essentially failed to gain mainstream adoption for 15 years. People called it an expensive toy. Same same but different.
First off, I'm not disparaging the content, I'm sure its good and useful in interviewing at most companies.
...that said. This kind of thing annoys me. You shouldn't have to study for an interview. Either you meet the requirement and have the experience or you don't. Reading books and stuff like this is really a cheat by the person being interviewed. You many have studied enough to "pass the test" but you really don't have a deep usable knowledge of the material and will likely forget much of what was studied.
When I do interviews I make sure the candidate is aware that studying will be a pointless endeavor and if I can tell your answers come from one of the interview prep books I'll end the interview early. My interviews ask questions that will tell me if you REALLY know the subject. For example if JavaScript is a requirement I'll throw this at you
const a = [1,2,3,4,5,6,7,8,9];
const b = a.filter(x=>1);
if(!!1 && b.some(e=>e>6)){
foo();
}
and ask you to tell me what it does. Its totally weird code and seeing that in actual code is highly unacceptable BUT if you really know JavaScript you will be able to tell me what this does in less than 30 seconds. Immediately if you're going for a Senior position.
1. Wow! That's so cool!
2. Why didn't someone this smart spend that time to build something that really matters?