Some dentists can be very proactive. Mine ID’d 2 small cavities but said if I focus on those areas they will probably not grow and be fine.
My wife’s childhood dentist gave her more than a dozen fillings for small cavities. If you ever get a dentist like that, I’d suggest to get a second opinion.
Don’t fuck around with your mouth health: dentures are not fun and infections there can be lethal. But another check-up won’t hurt if you think something’s off.
I think the 6mo cleanings are the prepare for people who don’t take good care of their teeth. My plan allows for 3/4 cleanings a year if I want them. And some people are a lot more prone.