The Avengers would have appreciated some help from Superman as they made an attempt to stop Thanos from wiping off half the universe but the Man of Steel could have proved to be the reason for their defeat in the long ride. The last son of Kryptonian has always saved the day and fought and won countless battles over his 83-year-old history.
Superman’s principles would’ve made heroes lose the fight, failing the entire universe!
When Thanos was fighting the Avengers and the Guardians of the Galaxy, his plan was to kill them all and take the Time Stone. After Iron Man was brutally beaten by Thanos, Sorcerer Supreme agrees to give the Stone for Tony’s life. At that time it seemed a horrible mistake, but all works out thanks to Doctor Strange’s glimpse into the future.
In Action Comics #1035, Superman made it clear that e doesn’t believe in predictions about the future when he goes on to Warworld against his son’s wishes. Jonathan had visited the distant future where he saw records that suggest this mission would result in Superman’s permanent disappearance.
Jon asked his father to rethink his plans but Superman refused as even his powers had started to become unpredictable. His sense of “righteousness” has always led him to do what is right no matter the odds.
This does make him a true hero, but it would have ruined and proved to be a huge disadvantage in the case of Strange’s long-term strategy against Thanos. Even if Doctor Strange had taken the pains to explain the truth about the futures he saw, Superman’s personal philosophy would have meant he has to fight to end and protect innocents by doing whatever in his power to prevent Thanos from gaining the stones.
Superman’s morals have often made him bump heads with other Justice Leaguers over a number of times. Even before he left for Warworld, he is formally kicked off from the team for his meddling in a potential war between America and Atlantis.
Of course, it is possible that Strange and other Avengers could have stopped Superman from attacking Thanos but they wouldn’t have been able to stop him!