I would say until he knows how to find you. Like, is comfortable getting to your room then you need to be able to hear him. If he’s still in a crib and unable to come on his own, I think you definitely need sound. Bc exactly what the other mama said, you never know.
I would definitely get something because for those few time he might get up you’ll need it. There are sound only monitors that have sensitivity hearing so it would only turn on when baby is actually crying not all the random noise. But I totally get you I wake at every movement and it’s super annoying.
We sleep on separate levels and I used a monitor. It’s set to go off if he is crying. It eases my mind to know if he needs me I can hear him.
You never know what may happen in the middle of the night. Poop, throw up, fever, etc. My daughter always sleeps through the night until a few months ago she got sick and the first indication was night waking crying with a fever. She had never done that before. Can you use a sound monitor on the lowest setting? That's what I have it on you don't really hear movement or light sound only crying.... or maybe leave his door open?