Nipple shields!!

So my baby is 3 weeks old and I've been using a nipple shield when I breastfeed since she was born, almost. When the NICU nurses gave it to me, they said something about weaning her off of it later. And I've seen one or two things since that mention weaning off the shield just as vaguely. My questions are: is that absolutely necessary at any point while breastfeeding and if so, when would that start being necessary? I'm kind of hoping that the only reason people wean off is because it's a small hassle to use?