For the sake of my story, we'll say that people get their visions whenever their desire for something related to one of the seven exceeds a certain limit, so if we were to say why did Kazuhiro receive his vision? We would say that's because he's desire or ambition to seek freedom of the world or something. Or Ayaka, for it is because her love for the people of Inuzuma and family. And for Razor, maybe it's something related to eternity, maybe living with his wolf family. And for Ningguang, maybe it's because she is willing to go out of her way to make sure that she doesn't break her contract or something idk. My speculation is that whenever they receive a vision, it is related to what the respective archon of that element is known for, and what god they were known as. Venti, God of Freedom, Anemo Archon. So when you receive an anemo vision, your ambition is related to freedom. And if you receive an Geo vision, then your ambition is related to contract somehow. Idk just go with it