if that is true then why does everyone need to do bullshit coding interviews instead of being hired for their projects and experience, degrees and track record?
Because employers _want_ people to be fungible. The quest to quantify and systematize hiring is a Quixotic effort at solving real challenges, but it persists because nobody has come up with an actual solution.
people have a long time ago, it’s called a university degree
also in the US employment is at will. not happy? fire the person.