For each job, you face a binary choice: take it or skip it. If you take it, you earn its profit but can't do any overlapping jobs. If you skip it, you keep the best profit so far. DP handles this decision at each step, and binary search finds the last non-overlapping job.
This pattern appears in any problem where you select non-overlapping intervals to maximize a value. Amazon uses it in ad auction scheduling and resource allocation systems. You'll learn when pure greedy fails (it does here) and when DP with a sorted structure is the right call.