Large companies tend to aim for standardization in the hiring process. They want apples to apples comparisons as much as possible, largely for legal reasons, but also for tracking metrics. Unfortunately, someone submitting high quality GitHub repo links doesn't fit a model where not many candidates are doing that.
Apple's hiring is not that standardized. Each team has their own process. There are some common themes, but they definitely don't all use the same tests. I've interviewed with a few teams there over the years (have ultimately turned down offers for one reason or another). I've had a pretty wide array of experiences, and incidentally, never a BST question.
I've also generally had very good experiences interviewing with them - tough but entirely reasonable questions focused directly on my expertise and the tech the team is using. One that stands out in contrast to OP's complaint was an interviewer that brought in a stack of printouts of screenshots of apps I'd worked on and used them to spark a discussion of the work I'd done on them.
OP's experience, while annoying, and not surprising, is also not universal at Apple.
Another point in case against overreliance on metrics. Optimizing your process for making it easier to measure can easily turn into looking for your keys under a lamp post on a street even though you've lost them in a park.
