It may be a regional thing. Also, the answers and comments you linked to don't specifically mention a time period, so what is meant by "regular" is somewhat open to interpretation.
In my area, it's typical to take your cat for a "regular" check-up annually. At this appointment, vaccines will be renewed as appropriate. The cat will be weighed to ensure that an undue amount of weight has not been gained or lost (which could be an indication of an underlying health problem). Temperature and heartbeat will also be checked. The vet usually also looks inside the ears and mouth to make sure nothing seems amiss there. Again, what is typical at these appointments may vary by region (or even from one vet to the next).
Certainly, I would advise taking your cat to the vet if you think something is wrong. But sometimes a vet may catch something at a routine check-up that you might not otherwise have noticed. (It wasn't until the vet looked inside my cat's ears that we noticed that her skin had changed hue and she was actually jaundiced!) While it's true that many health issues will manifest in ways that are obvious to the owner or casual observer eventually, it's often beneficial if these things can be caught earlier rather than later.
Also, regular check-ups mean that the vet has a useful baseline for your cat should an issue arise. This means that they know not just what's typical for cats in general, but what's typical for this specific cat which can be very helpful.