> I'll care about how they're thinking about it, how they react to my hints, how they act when they are stuck, if they ask for help or not, if they try to cover up what they don't know or that they made a mistake or are open and honest about it and treat it as an opportunity to learn, etc.
That's what you say, but in practice it's a guaranteed way to engage in discrimination at multiple levels using personal biases that are not present in a standardized test.
As I said in another comment, most of the best engineers I ever hired had bad grades or no grades at all - they didn't care about that and spent their time building real things instead. And on the other hand, some of the worst people I ever hired had perfect grades. Of course, this is not universal, and there is a large space in between - but I just can't agree with any usefulness of such tests. Real world engineering is totally different from any standardized tests..
How will a result from a standardized test tell me that their approach to engineering matches ours, and that they will fit in with their future team and company?
True, but using standardized tests for hiring is legally perilous in the USA. Employers can incur serious liability if they use a test which has a disparate impact on a protected class, and they can't prove that the test is directly relevant to the job.
That's what you say, but in practice it's a guaranteed way to engage in discrimination at multiple levels using personal biases that are not present in a standardized test.