Anime can be pretty melodramatic, so when the going gets tough, characters are often willing to lay down their lives for what they believe is right. However, good intentions don't always lead to desired outcomes, and some sacrifices feel utterly unnecessary.
Some pointless anime sacrifices are morbidly funny. It's hard not to smirk after Deidara of Naruto gets frustrated and blows himself up because Sasuke doesn't appreciate his art. However, they can also be devastating, like when Magical Girl Raising Project's Weiss Winterprison sacrifices her life to help her girlfriend Nana escape a bad situation. Weiss succeeds, but Nana is so devastated that she eventually commits suicide.
Dying for a noble cause take courage, but effective planning and a heavy dose of good luck are also pretty important.
After Vegeta realizes Buu is far too powerful to be taken down in a traditional brawl, he decides to end things using Final Explosion, a self-destruct technique that kills its user.
While his efforts are undoubtedly courageous, they're also totally ineffective. Buu regenerates shortly after Vegeta's attack and continues on with his reign of destruction.
Delinquent 14-year-old Yusuke Urameshi dies in an unprecedented act of bravery. For the vast majority of his life, he's acted like a selfish punk, yet he dives in front of an oncoming car to save a small child.
Unfortunately, it turns out the kid would have been fine without Yusuke's help. He was chasing a ball into the street, and the inflated rubber would have absorbed most of the car's impact.
In the afterlife, Botan actually chastises Yusuke for acting selflessly, as the kid sustained additional injuries from the soon-to-be Spirit Detective's intervention.
While in the heat of battle, it's usually a bad idea to base decisions on pride, and Deidara learns this the hard way when he squares off against Sasuke Uchiha.
While Deidara thinks of his explosive attacks as an art form, Sasuke doesn't feel the same way. To prove the hero wrong, Deidara unleashes his most powerful attack, which turns his body into a massive bomb. He dies when it detonates, but he hopes to take Sasuke out with him.
Even though Sasuke is exhausted, he still manages to survive the blast by summoning the giant snake Manda to serve as a shield. After this, Sasuke teleports to safety, making Deidara's final sacrifice utterly fruitless.
The Survey Corps Are Designed To Fail In 'Attack On Titan'
The Survey Corps is built around unnecessary sacrifice. The group's main goal is to kill as many Titans as possible, and every operation they embark on results in a massive human casualties.
To make matters worse, most of these suicide missions do nothing to actually advance the group's cause. Until the source of the Titans is discovered, killing individuals is meaningless, since new ones are constantly appearing.
These deadly excursions occasionally yield some useful information about the Titans, but this is a rarity, especially at the start of the series.