Derma rolling/stamping explanation needed

I see a lot of people who use derma rolling/stamping. Creating small holes in my head feels like it mainly creates damage. Can somebody explain me what it is used for and how it should improve the hair situation?

Reddit posted a full ‘How to Do Microneedling’ here: https://www.reddit.com/r/tressless/wiki/microneedling/

When microneedling is done correctly (controlled damage performed at least 10 seconds in each spot you need the hair to return). The Dr. Pen device offers the best product (see Amazon) as you can get the 34 needle type, length 1.25mm and use it from place to place until you cover your entire area that you are hoping to get your hair back. Once a week seems to be the most effective timing. The wounds that are created, are near the stem cells that trigger hair cycling. These cells don’t like the constant wounds, so they react with wound healing, a component of it impact the stem cells to trigger hair growth as part of the cytokine response by the body to the healing process.