u/Ok_Frosting358

Hello! Beginner here. I was taught to prioritize a 1 NT opening over a 1 major opening. My question is this: I have 5 hearts and all the requirements for a 1 NT opening. I bid 1 NT. My partner has 3 hearts. By not bidding 1 heart we miss the 8 card fit in hearts. Can you help explain the rationale a bit here? Thanks!