This is Ensign Harry Kim of the USS Voyager. And he is the most useless character of all time.
Kim has basically no memorable personality traits to him what so ever and most of his notable story moments revolve around him failing in some capacity, whether it's having the worst luck in the galaxy with women...
Kim had many failed relationship attempts while aboard Voyager. He confessed to a long-held infatuation with Academy classmate Lyndsay Ballard, who died during an away mission and was then revived by an alien race known as the Kobali. Kim's other failed infatuations include crewmate Megan Delaney, a holographic character named Marayna, and an alien terrorist named Irina. In 2374, Kim became infatuated with Seven of Nine shortly after she was released from the Borg Collective. Seven, however, did not return the affection due to her incomplete understanding of Human culture. When she confronted Kim regarding his feelings for her, she attempted to initiate an intimate encounter with him, forcing an awkward Kim to defuse the situation.
...Or causing the destruction of Voyager itself...
In yet another timeline, Kim and Chakotay flew the Delta Flyer to Earth after Voyager was destroyed due to a mistake of Kim's, an erroneous phase correction to the slipstream threshold of the quantum slipstream drive he chiefly designed... After Kim failed yet again to save Voyager, and with the Flyer, damaged by the USS Challenger, three minutes from a warp core breach, he completely fell apart, bursting into tears and bitterly accepting his final failure. The Doctor, however, would have none of it, and gave Kim the idea (which, due to his obsession with trying to get Voyager home, had not even crossed his mind) that, rather than preserving the slipstream, he should try to avoid the disaster by ending the flight before it was too late, a suggestion Kim excitedly realized was in fact possible. His broken spirit rejuvenated by the knowledge that, while a return to the Alpha Quadrant was out of the question, the ship and crew could still be saved, Kim succeeded at the last possible second by using The Doctor's mobile emitter to power the transmitter and send a message to Voyager, dying with his arms raised in triumph
He can't even properly fix his own mistake without needing someone else to suggest the actual idea that saves lives.
Harry Kim is so pathetically worthless that he straight up dies at one point, gets replaced with a duplicate of himself, and nobody cares enough to ever mention it again.
This dude is on the show from episode 1 until the very end of the series and never gets promoted. Tom Paris, his best friend over the course of the series, starts off in fucking Starfleet Jail, gets reinstated, gets demoted, and then gets promoted above Kim's rank all over the same period of time while Kim does jack squat. B'Elanna Torres starts off the show as an enemy of Starfleet and instantly outranks Kim by the time she puts on a proper Starfleet uniform. By the time Voyager ultimately returns to the Alpha Quadrant, Kim technically needs to address the bus boy from Quark's Bar as "sir".
Kim is the most worthless character I've ever seen in a TV show. I welcome you to talk about anyone else you think is this level of useless to their show.