Who would come to the house and vaccinate/examine everybody in big bunches, it was great! That's when I was fostering/rescuing quite a bit and we had a lot of people in & out of the house. So I went to a three year schedule for everyone, since my vet agreed they didn't need it every year.
Now I have three, strictly indoors, and I let it go even longer, since they go in for checkups or teeth cleaning every year or so and the vet can check them over, but since they get so little contact with other cats I don't bring them up to date more often than that, except for Rabies, which is required.
Circumstances vary, of course, depending on how much exposure they get and also their state of health. I don't have vets who make housecalls in my new area, so the stress on the cats is also something I think about, now that they are getting older they seem to hate it even more.
One time Mr. Bond was so determined not to go to the vet he broke out of his plastic carrier three times. He didn't lay a paw on us, just waited until our backs were turned and used his fifteen pounds on the plastic door. I wound up wrapping the carrier in duct tape to keep him in there. That's a way to get noticed in the waiting room!
We have a new carrier now.