Today books are our true teachers - not people

Steipler (Piskei Teshuvos vol 4 age 435:): ...In Orchos Rabbeinu (2:112) the Steipler is quoted as saying that the mitzva of greeting one’s teacher on Yom Tov is only relevant at a time when the Torah was learned orally and the student had acquired most of his Torah learning from his teacher. However in modern times since people learn Torah from gemora and other seforim – the concept of a master teacher is not relevant and therefore there is no obligation to great one’s teacher on Yom Tov. This that a person acquires a method of learning does not give his teacher a special status because it is possible for him to acquire this on his own. Furthermore who knows if the method he was taught was true. There is no obligation to greet a teacher who is not a master teacher on Yom Tov. This that we learn the halacha from the Shunamite woman because she greeted Elisha on Yom Tov - even though it is not relevant that say that he was her master teacher – is because Elisha was the teacher of all Jews and therefore everyone was required to greet him.