Construction cleaning is a sequence, and compressing it into one visit at the end is the most common way a handover slips. A pre-rough clear-out lets the next trade work. A rough clean after drywall and paint removes the bulk debris and dust that would otherwise be sealed into the finishes. The final clean is the detail pass: glass, fixtures, frames, floors, and every surface the client will run a finger along.
Dust is the real problem on a final construction clean. It settles out of the air for days after the work stops, which is why a building signed off on Friday can look dusty again on Monday. The re-clean exists for that, and pricing it into the schedule up front is cheaper than arguing about it at walkthrough.