For several years American Airlines has had a laser focus on ‘D0’ exact on-time departures. It hasn’t made them an on-time airline, but they’ve sacrificed cleaning, processing upgrades and standbys at the gate, and wouldn’t hold even the last flight of the day for connecting passengers.
Gate agents, used to getting called in for missing D0, and used to managers yelling at them as they try to get flights out, haven’t fully adapted to the need to prioritize aircraft cleaning in the Covid era on just pushing the aircraft back on time. Before the pandemic sacrificing cleaning to get planes out was the airline’s explicit policy.