My 10yo and 8yo brush their own teeth twice a day. They floss at bedtime. I buy kids’ flossers, so they aren’t dealing with winding thread on their fingers. They may not be doing a perfect job, but they do it willingly and there are no cavities yet. Although, we did recently find out that one or two of my younger child’s molars erupted with weak enamel. Apparently, there is a protective filling in her future.