I'm always baffled by all the discussions about flossing, as it's something that can be very easily verified empirically: one can just floss for a month, then stop doing it for another month, then resume and get a feeling for how the gums react. If they bleed or burn (lightly), then the efficacy is evident; if not... lucky person! No need for research either way.
In my case, I don't need to floss daily, but I still need to do it regularly. Two weeks without flossing, and I'll definitely feel the burn once I resume flossing.