Class 1A from My Hero Academia is, in a number of ways, similar to the Avengers, which naturally begs the question of how they would fare against Thanos. Both groups include individuals who possess a diversity of powers ranging from minor to mind-boggling.” Nevertheless, teams, even highly functioning ones, do fail, as the Avengers famous did in Endgame. But if Class 1A had fought the Mad Titan, would they do better?
The key to stopping Thanos’ snap did not require his complete defeat. Instead, removing the Infinity Gauntlet from his hand would have, in effect, ended his ability to complete the snap. In Avengers: Infinity War, removing the gauntlet was the Avengers’ initial tactic. Understanding, the immense strength of the Mad Titan, the Avengers used their individual abilities to pepper him with a vortex of hits, blasts, kicks, and gunfire that kept him unbalanced enough to impose a temporary restraint on his motion that gave them time to rip the gauntlet off his hand. Unfortunately, a momentarily lapse in their concentration, thanks to Star-Lord, allowed Thanos to literally, get the upper hand.
From a performance perspective, Class 1A has just as diverse a powerset as the Avengers. First, they can perform a plethora of physical attacks that would force Thanos on the defensive. For instance, Mina could use an acid shot to sting Thanos enough to disrupt his concentration. As he is recovering from that attack, Yuga could follow up with a supernova shot that knocks Thanos down, possibly disorientating him. To keep him from regaining his concentration, Uraraka could then unleash a zero-gravity burst to get Thanos off his feet and unable to generate the power he used in the punishing punches, kicks, and chokes he conducted against the Avengers.
In Infinity War, Dr. Strange uses his cape to temporarily stop Thanos from closing his fist, with limited effect. However, Minoru Mineta could use his “sticky balls” to keep Thanos from closing this hand. As he tries to rip the balls off, Kaminari and Todoroki could combine forces with an electrocute-freeze attack that knocks Thanos unconscious but yet exposes his arm, up to the end, of the Infinity Gauntlet. While under ice, Deku and Sato should have as much time, if not more, than Spider-Man and Iron Man had in the movie to pull the Infinity Gauntlet off Thanos’ hand. Momo could provide further assistance by creating an unbreakable crowbar that all three could use to further loosen Thanos’s grip on the gauntlet. If that did not work, Bakkugo could just use his explosive power to blow the gauntlet off.
All in all, Class 1A has a diversity of skills that the Avengers were lacking in their attempt to stop Thanos. If Class 1A conducted the operation in an orderly, well-thought-out plan, there is nothing to suggest that they would be less successful from the experience than the Avengers. The diversity of skills that they bring to the battle makes them, on paper, more likely to be able to separate the Infinity Gauntlet from Thanos. The only issue, which is one of the key elements of My Hero Academia manga is, that Class 1A are high school students learning how to deal with becoming an adult as well as handling their superpowers. That is, unlike the more mature Marvel's Avengers in addition to becoming superheroes, Class 1A is also dealing with becoming adults. Consequently, unless My Hero Academia's Class 1A can come up with a serious battle plan, the chances are that Thanos would barely break a sweat in defeating them like he did with the Avengers.