Complex interview questions do test technical know how but they also test for an emotional response. If one poses frustrated, defeated, angered, irritated, confrontational, arrogant, or even defiant, the interviewer will end the interview early. The problems are hard, but being able to walk through your thought process - even with feigned confidence - will make you pass the test. Yes, actually solving the problem will put the final nail in the future proverbial 9-5 coffin, but don't let emotion get the best of you. I agree the process is broken, but I'll game it to the end
depends on your definition of "test". i've yet to meet a trained interviewer, myself included. i've been doing this for ages, and in my own mind i do think i am better than average at interviews and assessments. (without a useful rubric to judge against, take that with a grain of salt.)
if i am to judge by only "vocal minority", ie negative feedback, services like triplebyte and Karat are the same. the interviewers are poorly trained. i would never do that kind of interview so i don't have firsthand knowledge in those cases.
emotional response to a problem beyond your capability (kobyashi maru) isn't what the interviewer is going for. i agree, there is a component. that isn't the same as actually evaluating soft skills.
to bring it back home, i remain unenlightened how my first comment demonstrates a failure of soft skills! thank you for the discussion.