Human beings are smart, and we keep inventing new things. In medicine, that means more and better tests to analyze us in increasingly sophisticated ways. This trend will continue, so we need to get used to it, and be smart about it.
Sometimes when tests get better, they are able to identify more subtle things. For example, years ago we would diagnose a pulmonary embolus ("PE," a blood clot in the lungs) mostly by using a ventilation/perfusion scan, which gives a rough idea as to whether a large chunk of lung has a blood clot in it. We know that if there is a large clot, the patient needs to be anticoagulated with warfarin, for at least a few months.
Then we began diagnosing PE's with CT scans. This was an improvement, because they are easier to do, can be done on less stable patients, and give a clearer picture. On a CT angiogram, you can actually see the clot. The following picture shows a really bad one, called a "saddle PE," that stretches across both pulmonary arteries.
(Source: https://commons.wikimedia.org/w/index.php?curid=53722435). In a CT scan, dark means less dense and white means dense. A dense "dye" is injected into the blood to make it appear lighter. The dye does not go into the clot, so now you can tell where one ends and the other begins.
These days, CT scans are becoming increasingly excellent, to the point where very small clots can be viewed in the lung. But there is a question whether these small clots are as dangerous as the big ones, and whether the patient actually needs anticoagulation. It's currently controversial.
Does this mean we should stop testing? No! Medical care is quite good and quite helpful, overall. We just need to be careful.
One answer to the problem of new technology is to do different kinds of research. A new technology that sees subtler things should make us stop and ask ourselves if this is still disease. And in fact, these are the questions that researchers are asking now.
While we wait for the scientific consensus to evolve, it's important to ask questions and weigh what we know of risks and benefits.