That's assuming you want to hire the first person that can do the job.

The companies that popularized this were and still are EXTREMELY lucrative, and get a TON of competition.

They can afford to be choosey. So they can try to find not only the person who can do the job but also do it BEST.

And that's really hard to tell from just looking at their work experience. You want to see how their brain works under pressure, dealing with an ambiguous new problem they've never seen before.

A lot of people who rag on modern tech interviewing don't get this. Unfortunately, so do a lot of people DOING these modern tech interviews. "He said the algorithm was O(n log n) but the answer is actually O (k log n). Not inclined"

And so, we spiral.