My Hero Academia focuses on great superheroes who can save the day, and while not all heroes actually seek fame and glory, many of them become household names, such as the one and only All Might. Izuku Midoriya is training hard to replace All Might, as is Katsuki Bakugo, but let's not forget about support heroes, like Hanta Sero, who can help keep a team together.
Not all trainee heroes are looking for fame and adoration. Mina Ashido is confident but somewhat humble, and the same can be said of Hanta Sero, the tape hero. True, he likes to show off sometimes, but not to the same extent as Bakugo or Shoto. He is a classic support hero, and those are important.
Hanta Sero's Binding Quirk Is More Useful Than You Think
Some Quirks, such as the devastating One For All or Bakugo's Explosion Quirk, are meant to take center stage and fight the villains directly. Then there are Quirks like Momo's Creation Quirk, Yuga Aoyama's Navel Laser, and of course, Hanta Sero's Tape, all of which are effective for backing up a melee hero during a serious fight against villains or criminals. Alone, Sero's Tape Quirk is mediocre at best, but his Quirk can easily combine with others to totally turn the tide of battle.
Sero is able to eject long, tough strands of tape from both elbows, and that tape can quickly be tied around a villain to restrain him or her, or it can tie multiple villains together to prevent them from fighting or escaping. Or, that Tape ability can be used to leash a villain's arm or wrist to the terrain and make them an easy target for someone such as Izuku, especially if that villain is highly agile or quick on their feet. Hanta Sero's Quirk can't easily knock someone out, but it can restrain a villain until a hard-hitting ally can finish the job.
Not only that, but Sero's Tape ability can be used for search and rescue purposes. His tape can quickly form bandages for an injured civilian who has suffered a sprain or broken bones, and it can be used to hold the pieces of a damaged building together until all civilians can be evacuated. This Tape Quirk can also be used to block off an area to prevent civilians from wandering into a combat zone, or prevent villains from escaping. Tangible Quirks like this one are highly effective when they can be used to create solid objects, just like the ice of Shoto's own Quirk or Cementoss's concrete formations. Hanta Sero can do it all.
Hanta Sero's Personality Matches His Quirk
It may also be noted that Hanta Sero's personality matches his Quirk and his support hero status -- and something similar can be said about Momo Yaoyorozu and Koji Kodai as well. These students are brave in the face of danger, as all of class 1-A's students are, but they are not brash or reckless, nor are they seeking glory, which sets them far apart from Katsuki Bakugo and Shoto Todoroki.
Put another way, Hanta Sero doesn't have a pathological need to prove himself, and he is clearly content to slowly and surely build a reputation as a reliable and cooperative teammate. He's not anxious to become #1 or become the superstar; he'll let the heavy hitters take care of that, while he does his job with or without acknowledgment. Sero would love a compliment or a thank you, but it's not a priority. That's a good attitude for a support hero to have.
As a student, Hanta Sero has unimpressive grades, scoring in the bottom quarter of his class -- but he took responsibility for that. Sero studied hard for the midterms and sought help from Momo, the class's top student. This shows that he is diligent, humble and optimistic despite his modest performance as a student, and there again, that's a good attitude for a support hero.
Sero did fail the 2-vs-1 battle against his teacher Midnight, and he quickly lost to Shoto in the U.A. sports festival, but neither of those defeats dampened his spirits. Sero accepted what happened and moved on, patiently and diligently, and he didn't let any of this damage his pride. He's happy to work hard in the background and contribute to the team when necessary, and he is also laid-back and highly cooperative in nature. That's exactly what Izuku, Bakugo and the others need from him.