Bald for many years, can microneedling grow it back?

Does it? How does collagen help a hair cell which is dead in regrowing hair? I think it is the stemcell transfer that happens during the microneedling that help dormant cells to actually regrow back. Any thoughts?

Probably not if the area has really been bald for many many years. If it has been just a couple of years, some of the stem cells might be stimulated with microneedling plus minoxidil.