I used to go every six months. It’s been about three years now.
Like @jonsblond, I brush and floss daily. Every dentist I have been to said the same thing: If you are only going to do one thing to protect your teeth, floss. I haven’t had a cavity since the braces came off at the age of 14. My retainers from that time (almost 40 years ago…gad!) still fit.
At the slightest hint of a problem, I’d schedule an appt. And if I had dental insurance, I’d go back to having them cleaned every six months. It’s an enjoyable experience for me.