Because Piggy knows how to blow the conch but Ralph is the one who actually blows the conch
Ralph represents the leadership and authority associated with the conch, using it to maintain order and call meetings. Piggy, on the other hand, provides intellectual support by advising Ralph on how to use the conch effectively and reminding him of its importance. Together, they form a balanced partnership that combines physical and intellectual strengths in managing the group.
Piggy advises Ralph to blow the conch to gather everyone because it is a symbol of authority and order among the boys. Ralph decides not to blow the conch because he is frustrated and disheartened by the boys' lack of respect for rules and order at that point in the story.
He tells Ralph to blow the conch
He suggests Ralph to blow the conch shell
Read the story -___-
Piggy suggests that Ralph should blow the conch shell to gather the boys and reestablish order and civilization on the island. He believes that the conch represents authority and should be used to maintain a sense of structure and unity among the group.
When Roger launched the boulder from the top of Castle Rock "with a sense of delirious abandonement," it struck Piggy a "glancing blow" and the conch "exploded into a thousand white fragments and ceased to exist." Piggy then travelled sideways through the air and fell forty feet to land on his back on the square rock in the sea. "His head opened and stuff came out and turned red."
When Ralph first spots the conch in the lagoon Piggy tells him, "I knew a boy who had one of those, on his garden wal it was, they are ever so valuable." He later tells Ralph that the boy, "he used to blow it to make a noise," and explains to Ralph that the boy blew from his diaphragm in order to get a noise from the conch shell. So although Ralph actually finds, recovers and blows the conch. Piggy identifies it correctly and informs Ralph that it can be blown.
Ralph rejects Piggy's suggestion to blow the conch to call for a meeting after the assembly breaks down. Ralph believes that the conch has no power to control the boys anymore and that they need a more concrete plan to maintain order on the island.
the Conch is destroyed along with Piggy Page 181 " The rock struck Piggy a glancing blow from chin to knee; the conch exploding into a thousand white fragments and ceased to exist." Piggy is holding it up for order, and then Rodger leans all his weight onto the lever, than causes a bolder to fall; killing Piggy, the symbol for the adult world, and destroying the conch, the symbol for civilization. Jack then states that since there is no conch, then their tribes doesn't exist, he then proceeds to declare himself chief and tries to kill Ralph with his spear.
Quote 57: "The rock struck Piggy a glancing blow from chin to knee; the conch exploded into a thousand white fragments and ceased to exist." Chapter 11, pg. 164.