The other cyclopses didn't help because Odysseus introduced himself as Nobody, so when Polyphemus said that Nobody poked his eye out, the cyclopses thought he was kidding. Odysseus did this on purpose
Blinding Polyphemus allows Odysseus and his men to escape from the cave without being detected by Polyphemus. Killing him would have likely alerted the other Cyclopes and made their escape more difficult. Additionally, blinding him adds an extra layer of humiliation and revenge for the harm Polyphemus inflicted on Odysseus and his crew.
Odysseus tells Polyphemus that his name is "Nobody." When Polyphemus asks for help during an attack, Odysseus and his men blind him using a wooden stake. When Polyphemus calls out for help, he tells the other Cyclopes that "Nobody" is attacking him, so they do not come to his aid.
The other Cyclopes think Polyphemus is saying that "Nobody" has tricked him. This is a clever play on words by Odysseus when he tells Polyphemus his name is "Nobody," so when Polyphemus shouts that "Nobody" has tricked him, the other Cyclopes do not understand that he is actually in trouble.
Odysseus cunningly told the cyclops, Polyphemus, that he was named "Nobody". As a result, when Polyphemus was screaming in horrible pain after Odysseus (Nobody) stabbed him with a stake in the eye, the neighboring cyclopes yelled to Polyphemus to see if he needed help. Polyphemus responded that Nobody was attacking him.
The other Cyclopes refused to help Polyphemus because they believed he was being punished by the gods for his mistreatment of Odysseus and his men. They did not want to anger the gods by interfering in the situation.
He lives with other cyclopses.
Cyclops were a race not an individual. In Homer's Odyssey, the hero Odysseus encounters the Cyclops Polyphemus, the son of Poseidon and Thoosa (a nereid), The other Cyclopses were offspring of Gaia.
In Homer's "Odyssey," Odysseus is insulted by the Cyclops Polyphemus when he asks for his name and Odysseus cleverly responds with the false name "Nobody." When Odysseus and his men blind Polyphemus and he cries out for help, the other Cyclopes assume that "Nobody" is hurting him, leading Polyphemus to feel humiliated and insulted.
Polyphemus cries out "Nohbdy, Nohbdy, tricked me, Nohbdy has blinded me!" This is a part of Odysseus' clever plan to escape from the cyclops. Polyphemus' scream leads the other cyclopes to believe that nobody harmed him, allowing Odysseus and his crew to escape unnoticed.
He got over confident, and wanted Polyphemus to spread the word on who defeated him, so other creatures would fear him. He did not think, however, that Polyphemus would instead tell his father (Poseidon) to get revenge on Odysseus.
Odysseus gives Polyphemus a fake name, "Nobody," so that when he blinds Polyphemus and calls for help, the other Cyclopes would think that "Nobody" harmed him and wouldn't come to his aid. This clever deception allows Odysseus and his men to escape from the Cyclops' cave.
When the other cyclopses came to see why he was yelling he told them that NOBODY was hurting him, meaning the person he thought to be called Nobody but the other cyclopses thought he meant it in the sense we use it as nobody meaning no-one.
Blinding Polyphemus allows Odysseus and his men to escape from the cave without being detected by Polyphemus. Killing him would have likely alerted the other Cyclopes and made their escape more difficult. Additionally, blinding him adds an extra layer of humiliation and revenge for the harm Polyphemus inflicted on Odysseus and his crew.
Odysseus told the giant cyclops Polyphemus that his name was "Nobody." This clever ruse allowed Odysseus to outsmart Polyphemus later when he blinded him; when the other cyclopes came to investigate Polyphemus's cries for help, he could only say that "Nobody" was hurting him, leading them to leave him alone.
Polyphemus attempts to trick Odysseus and his men into revealing where their ship is, among other information. There is no need for him to be overtly antagonistic until he wants to eat the men.
It enables Odysseus and his men to escape the Cyclops's cave and it confuses the other Cyclopses so they don't come to the aid of their friend.
Odysseus tricked Polythemus by telling him that his name was "Nohbdy." When Polythemus shouted for help, he yelled "Help, NOHBDY has blinded me." When the other cyclopes heard that NOBODY had hurt him, they laughed and went back to their own business.