One of the issues in the now infamous meta analysis was that many of the studies analyzed found some benefit, but they were low quality studies. So this doesn'

One of the issues in the now infamous meta analysis was that many of the studies analyzed found some benefit, but they were low quality studies. So this doesn't necessarily mean that flossing doesn't work. It may just mean that dentists are already making money hand over fist and don't care enough to do good studies and validate that. BTW what was specifically looked at was whether unsupervised flossing works. So another possibility is that flossing properly works but a lot of people do it ineffectively. All things you would want a conscientious, science-based ADA to care about