It's an old-school trick to help stubborn, old, or poorly stored seeds to germinate (by allowing more oxygen into the seed). It's also used to prevent damping off (which is one of the main reasons seedlings die). I use it 100% of the time for all seeds, and I too have 100% success rate since I started doing it. A capful of 3% peroxide into 20 ounces of distilled water (PHed if needed). Then do the paper towel method, and this treated water is the only thing that touches those seeds/seedlings until they go into their much larger veg pots (unless they need a mild fert and I add peroxide to that too). I had a serious issue with damping off, and it never happens now.
Long term use of peroxide can harm soil microbes, so don't use throughout the plant's entire life.