Haaland did a great job to make Manchester City win a title.
Haaland didn't make Manchester city to win a title, rather it was Manchester city that made Haaland to win a title. Manchester city is used to winning titles while Haaland wasn't used to winning titles until he joined Manchester city.
Exactly Haaland is not a key component for Manchester City’s success this season, even without him, Manchester City will win the league because he was not the my important player in the squad.
Last season, I will agree with @Rebekker that Manchester City’s success depends on Haaland goals because he was the main man in the squad that score the most important hold that determine their success in their last season’s Premier League championship.
Haaland is one of Manchester City's most important players and is generally regarded as the main striker. When the opposition team takes the field against Manchester City, the opposition team will always try to stop the Manchester City attacker who is there, so if two or three defenders are behind him at all times, they will. When the opposing team makes all preparations to stop a team's main striker, the manager of this team makes plans with the other players available. This is because when the opposing team's defenders block their main striker, another player will score at that opportunity. Haaland is really a very strong player because he does his job properly no matter how much he is hindered, which is why Manchester City rely on him so much.