It's always been strange to me that tech interviews tend to check for basic CS, rather than deep engineering.
When was the last time you had to implement bsearch() in a real project?
When was the last time you had to implement bsearch() in a real project?
On the other hand, many so-called real world questions measure only how well you are able to recite from API documentation of interviewer's favourite framework or at best the language specification.
It is certainly false that if you are able to get CS basics right, you will NECESSARILY be any good at deep engineering.
There are people who get the basics right and are good at deep engineering. The question is whether one predicts the other.