I’m a school teacher. In a smaller setting (such as not having 100s of students in a lecture hall) I don’t need tests to know where my students are academically and if they’re capable of moving on. It helps, but it’s genuinely overrated. The main purpose it serves is putting an actual number/letter that corresponds to their level of understanding that they and everyone else has access to. I don’t need number/letter grades to know which students are excelling, which ones are average, which ones are lower performing, which ones need extra help now and possibly at the next level, and which ones need to be held back. The grades are realistically for everyone but me; so they can see what I’m seeing without being there every day and so my opinions are justified. There have been a few students who’ve surprised me with their test grades, good and bad, but they’re the exception. And after a test or two, there’s really no surprises anymore.