I think you're conflating latency and bandwidth. The total amount of time spent actually studying a given fact with spaced repetition (to get it in long term memory) is comparable to the amount of time spent studying that fact when cramming for an exam. The difference is that that time is spread over months instead of over a few hours. The bandwidth is roughly equivalent, but the latency is much higher.
So if you use SRS effectively, you can actually spend considerably less time studying. If you cram for each test, you're essentially crunching a bunch of data into short term memory, forgetting it, and then having to crunch a lot of it back in for the next exam. Then, for the final, you end up having to cram all of it in. Essentially, you're paying the cost of short term memorization over and over again, every time you have an exam.
If you use SRS and use it daily over the course of the entire semester, you'll only pay that cost once. And since you'll still have the information in your brain in between exams, your mind will be able to more effectively connect new information to old than if you cram and forget.
So if you use SRS effectively, you can actually spend considerably less time studying. If you cram for each test, you're essentially crunching a bunch of data into short term memory, forgetting it, and then having to crunch a lot of it back in for the next exam. Then, for the final, you end up having to cram all of it in. Essentially, you're paying the cost of short term memorization over and over again, every time you have an exam.
If you use SRS and use it daily over the course of the entire semester, you'll only pay that cost once. And since you'll still have the information in your brain in between exams, your mind will be able to more effectively connect new information to old than if you cram and forget.