In any area of programming there will be specialized knowledge required. Often within that same area different companies will have chosen different approaches.

Thus a stupid set of interviewers will start throwing out questions which they could not have potentially answered even months before they gave the interview.

For example, dealing with huge amounts of sensor data requires all kinds of timeseries expertise. It can be picked up very quickly, especially if you are in an organization which has already stumbled down all the deadends. There are also many different timeseries databases which are fairly different than each other.

In the above example you could have two different companies, each with successful sensor data solutions, interview the other group and reject them because they used a "different" approach.

The reality of a great programmer is not what they know, but their ability to learn what they need to solve the problem in front of them right now.

As I have said many times, I could take any language I know well and write up a programming quiz where I would fail miserably. Just take C++ keywords. Give this quiz to ab "Expert" what is the keyword compl used for? You could yell in their face how they don't have an encyclopedic knowledge.

If you talk to someone who makes games using C++ they will be see the world differently than someone who makes safety critical embedded systems. Their use of the same language will be almost as if they are using two different languages.

You dodged a bullet avoiding a company where academic knowledge is more important than being a good programmer.