Goku is a Saiyan from Universe 7 and the main protagonist of the Dragon Ball series. His powers seem to know no bounds. Goku recently clashed against Moro, and although he lost initially, he did much better in the second round. In his Mastered Ultra Instinct form, Goku would certainly be strong enough to defeat Moro.

Who kills Moro?

After Moro was covered they shot him ten times. According to the official reconstruction after a series of trials, the killer was Mario Moretti. Moro's body was left in the trunk of a red Renault 4 on Via Michelangelo Caetani towards the Tiber River near the Roman Ghetto.

Why did Goku not kill Moro?

His hair turned silver, and Whis confirmed it was the Ultra Instinct form. Moro managed to level up his power to keep up with the fight, but it wasn't enough to match Goku's new form. As Goku's attacks improved, Moro couldn't hit him even a single punch.