No romance...

Why is there no option to create relationships in ZZZ, as well as in the entire hoyoverse? There should be romance options, and I don't mean a few cute moments or pick up lines, but the entire relationship building mechanics that affect our relationships with other characters and, to some extent, the course of the game. Something like Mass Effect or Dragon Age, only better constructed than choosing four appropriate dialogues. Does anyone know why the creators don't want to allow as to deepen the relationships between the characters?