I'm 50 this year and I don't have any fillings. There's nothing wrong with my teeth. I eat a balanced diet hardly any sweets and no fizzy drinks (main because I've never liked them). I'm also probably just a bit lucky with my teeth.
I brush regularly but find flossing really uncomfortable so rarely do it. I see the hygienist three times a year to get rid of any build up.
Every time I go to the dentist or the hygienist, I get another lecture about brushing and flossing. I know technically it's just advice but the tone is definitely "telling off".
Really, I'm a 50yo adult who's teeth are in remarkably good condition, I can't be getting it that badly wrong. And if I do have any failings, I pay these people handsomely to deal with it!
Actually, by this stage in life, I'm not at all convinced such regular visits are necessary, but obviously no dentist is going to tell me that.