HP: How come time travelers also do wholesale?

[The protagonist is not a good person/no heroine/system/no one is a good person/if you don't like it, please don't enter] Yan Ming is an ordinary single young man. He accidentally traveled through time with the system and became Harry Potter. He thought he was the only one who traveled through time. He endured humiliation for eleven years and finally came to Hogwarts. But... Harry: Odd changes but even does not change? Ron: Symbols look at the quadrant? Harry: Come on! Hermione: ABC! Harry: Damn, they are all travelers. System: This... I really didn't expect it. Malfoy: Then... a lone brave man? Snape: ... Fight. Harry: System, how can you, a traveler, also bring wholesale? "Why do travelers also wholesale" is also known as "HP fan group building moment" System: I don't understand this either, why don't you ask Dumbledore? Dumbledore: How should I know, I also traveled through time. Only Harry (Yan Ming) has the system. ...