I'd say it's neither old nor young. I believe it's like the 30s/40s of cats.
My cats are also pretty healthy otherwise - they're even older now and the vet always says she'd believe it if I said they were 5 by their muscle tone etc.
My cat is 14 and has never had a cavity and she pretty much just eats high quality dried food along with a bit of canned food every day. Not pure bred, she's a mutt.
Wasn't my intent on that. I was thinking in comparison to elementary school kids. Also just curious, all told.
My expectation would be that mutts have healthier teeth. And general health. That said, that expectation isn't strong enough that counter would shock me.
My cats are also pretty healthy otherwise - they're even older now and the vet always says she'd believe it if I said they were 5 by their muscle tone etc.