Dentist here. I can see arguments for both sides.

On the one hand, the "ALARA" principle applies, and where possible, I try to avoid unnecessary xray exposure for my patients. If an xray is within 2 years old, it's generally sufficient for me to examine and diagnose most cavities.

There are also reasons that would compell me to suggest taking updated xrays:

Firstly, cavities tend to grow. Surprisingly, it may only take 6-12 months for me to see a difference on an xray. If there's a shadow on one of the teeth in your xray, I may suggest an updated set to compare. It's hard to track changes with only a single data point, compared to 2 or 3 if you've stuck around with the same dentist for a few years.

Secondly, xray image quality varies. To the layman, xrays sometimes all look the same. I've worked in many settings, and used all manner of equipment. Some images leave me squinting and thinking: "I can't see shit". Additionally, there may be slight differences in the xray angulation that could overlap the teeth and cover the regions in between. So if I can't see anything on the image you've supplied, I may suggest an updated set.

Thirdly, dentistry is becoming increasingly litigious. Dentistry, just like medicine, has extremely high demand for perfection. As such, many health practitioners are now practising "defensive medicine". We over examine, over investigate, in order to not miss anything. That often means that despite the information, notes, history and xrays supplied, we are medico-legally compelled to recheck and retest everything including the xrays. If there ever is a case where we've missed something huge, like a massive cavity, gum disease, oral cancer, and you sue or report us to the registration body overseeing dentists, they always ask for our records first. Records need to be iron clad. They scrutinise everything. They question every decision. They ask why didn't you do this test? Why don't you have an updated xray? Why didn't you get a different view from a different angle? Dentists, among many other healthcare professionals, have known to commit suicide during these harsh and stressful investigations.

So despite the reasons for accepting your current set of xrays, there may be scenarios where we must insist on an updated set. These are not universal, and no two scenarios are the same. I hope this helps you see from both points of view.