The problem is congested rtf, but perhaps i 'm reading too much in to the title of the thread.
Seeking clarification is undoubtedly the correct course of action. Having been "CLEARED for the approach" why is further clearance routinely asked for by some?
(Are some pilots routinely unsure of what they have been cleared to do?Would that not constitute a competency issue? )In a busy atc environment, it contributes significantly to RTF congestion.
It has also been known to create confusion. A good example is an EXAM flight flown by a student from a reputable training organisation was cleared for the approach, once beacon outbound the student made the beacon outbound call as descent with the procedure was commenced, atc said "descend with the procedure, report base turn complete". The student thought he must have descended without clearance and, confidence shattered, flew a less than average approach. For the remainder of the flight he was distracted. Thankfully, and understanding examiner was aware of the situation and able to issue a pass with minimal additional flying. doubtless that pilot now has a generally low opinion of ATC and their ability to be consistent.