Él vino de nuevo después de una semana.

why is the verb “venir” and not “volver”? e.g. “Él volvió después de una semana”

Edit: I asked Chatgpt and it gave the answer of difference in focus between “venir” and “volver”; “venir” places focus on the speaker as the reference point, while “volver” places focus on the location the the subject is returning to (not necessarily where the speaker is at)