A guest's first impressions come from the spaces you share with everyone: the porte cochère, the lobby, the lift and the hallway to their room. Smudged lift doors or a worn path in the corridor carpet end up in online reviews, and those reviews shape bookings.
Hotels never close, which is where standards start to wobble. Daytime crews are well supervised. Overnight and weekend shifts are thinner, and jobs like resetting a conference room after a late dinner can fall between teams. Nobody notices one miss. Guests notice a week of them.
General managers and front office leads already juggle occupancy, staffing and complaints. Following up a cleaning contractor should not be on that list.