Well, for a starter he is the most well-written character in the manga. He bullied Deku when he was a kid up to middle school, but he gradually mature. He doesn’t like fellowships, and in his road to becoming a hero, he forgets to consider other people or just because he doesn’t give a fuck.
People also like him for comic relief the author has portrayed.
Horikoshi have brought the reader from this surprise to another. The constant anger, his determination, the aggressive and arrogance that hides a brilliant mind. A fair man who won’t take what he doesn’t own. He more prideful, aggressive and arrogance than anyone else in the series. Even the villains also see his potential but why would he want to become a villain. Bakugou is a boy who has everything: a great quirk, a happy family, and peaceful infancy. He has everything he ever needs. And he believes he will get everything he craves.
The author gives the character so much deep and complexity. With everything he has, Bakugou still suffers from his superiority complex. He has the most significant developed. He matures every day through everybody he met. He might have a look of a gangster, and his anger behavior will give people a wrong expressive. He is at the top of his class, not only in battle but also in studying (even higher than the main character). A fair man who won’t take the medal that he didn’t earn the rightful way.
The kind of coolness his personality portrays on the show, in contrast to Izuku’s sincere, innocent way, really puts things into focus when you notice how different people can be.