I can say that I think I have perfect looking teeth because I brush and floss. Especially because of flossing. My gums are healthy and don't bleed when poked. The dental nurses that clean my teeth compliment me on doing a good job. Instead of worrying about seeing the dentist, I worry about getting a hot nurse.
If you don't floss, your mouth smells like death because bacteria is trapped between your teeth and just below the gum lines.