In general, colleges will care more about AP course grades before a student is admitted and AP test grades afterwards. Unlike AP test scores, AP course grades are part of a student's high school GPA, which is a significant factor for college admissions. AP course grades become even more significant if your high school weights GPA based on course difficulty level, since a high AP course score can significantly boost a weighted GPA (a 4.0 in an AP class can become a 5.0 or even a 6.0 on your transcript, depending on how your high school weights GPA). Plus, many students take AP courses in May of senior year, far after most college admissions decisions have been made.
While it's true that colleges don't necessarily use AP scores as a criterion for admitting students (as much as they do the course grades, at least), though, that doesn't mean that the tests and AP scores are worthless. It may be true that some top-tier colleges are no longer giving credit for AP exams, but these schools are definitely not in the majority. Even if you don't get out of freshmen requirements because you took AP classes, AP scores of 5 can still help place you into a higher level class, or give you credit towards your degree.
I can speak to this from my own experience at Wellesley. You could submit up to four AP scores and receive one credit for each towards your degree (and for a 32-credit degree requirement, this was nothing to sneeze at). I ended up submitting my scores for AP English Literature, European History, Macroeconomics, and BC Calculus. While I got credit for each of these exams, I wasn't able, for example, to get out of the Math requirement with my BC Calculus score. Instead, I was placed into Multivariable Calculus (with the understanding that if I took a lower level class, my AP score would be invalidated). The plus side of this was that not only did I get credit towards my degree for much less than a summer course/other credit would have cost, but that I got to take classes of the appropriate level and move on to the fun classes (like Number Theory) more quickly.