this clearly doesn't work because most test questions for students are trivially Google-able. So then tests as they currently exist would not be able to differe

this clearly doesn't work because most test questions for students are trivially Google-able. So then tests as they currently exist would not be able to differentiate someone who has studied and internalized the material from someone who Googles quickly. Tests would have to be re-written to require a lot more creativity, which is not only hard to do as a test writer, it's harder to grade and ultimately for students, requires even more effort (compared to rote memorization of facts or rules). So I don't think most students or instructors love this idea.