And they care about the score mostly for placement (hence the test name). I’ve had multiple T25 school AOs tell me they don’t even see AP scores as part of the file they are evaluating.
If you’re learning a new topic because you are very interested, and you don’t have access to it, or couldn’t fit it in your schedule, at school, that’s great. And you might as well take the test. But don’t do it because you think it’s a meaningful admission advantage