Oscar Piastri admits he must ‘do a better job’ after a disappointing time at the Mexico City Grand Prix, with the McLaren driver hopeful of never doing one thing again in F1. The 23-year-old is now approaching the conclusion of his sophomore season in the pinnacle of motorsport. But while Piastri became a Grand Prix winner for the first time this July in the Hungarian GP and won again in Azerbaijan, results have started to dip since winning in Baku. Piastri endured his troubles in the Singapore GP en route to a third-place finish as teammate Lando Norris won ahead of title rival Max Verstappen…