Doesn't have to be a standard IQ test, I would be fine with the test being about algorithms and systems design type questions. Just please remove the biased human component from interviews and use a more standardized metric across a group of people instead of randomly chosen questions for each candidate with subjective evaluation. The current process is not great even for people with good tech skill due to the randomness and subjective evaluation factors.

Also you are wrong about standard IQ tests not being able to measure relevant skills for tech companies. They not perfect but I bet even those would do a better job than the current process. The psychometric research is clear that they are useful for predicting results across a wide variety of domains.