The reason this rings wrong for people is because the reasons early testing is dangerous are entirely social. People are motivated by fear to have every test available, doctors are motivated by fear of being accused of neglect by the patient, doctors are also motivated by the profit that they make from the tests, the manufacturers and patent-holders of tests are motivated to have them done as much as possible, the labs that do tests make money on the number of tests that are done, the nonprofits that campaign based on diseases are expected to message to increase testing for those diseases and accept money from manufacturers and patent-holders, there's motivation to exaggerate the danger of what's detected by the manufacturers and patent-holders of treatments for the disease, and there's motivation by researchers who formulate the criteria for determining whether a particular feature of something detected is potentially dangerous/deserves treatment, and a motivation to give them the most expensive treatment, regardless of whether that treatment is unpleasant; in fact if the treatment is dangerous, it opens up secondary markets.

There's just an enormous number of tailwinds pushing overdetection and overtreatment. The sum of that is what's important, which is that when you test earlier, you often objectively end up with more death and suffering. Which is what a state-run national healthcare systems needs to look at, they can't get lost in the trees. You pick an optimum age for testing that shifts the balance to less suffering and death (and costs), and you look for specific exceptions (genetic, lifestyle, comorbidities) and test just those people early.

Could there be a way in which all testing would help instead of hurt? Yes, but it's political and psychological and not likely to ever happen. You'd have to (as a patient) trust probability in general, and additionally you'd have to trust the probabilities that they're handing you haven't been distorted by the self-interest of others. Not likely for the foreseeable future; maybe 1000 years from now.

If you want to do the study, all you have to do is compare the number of deaths from a thing when people are tested early to the number of deaths when people are tested late. Or just look for other people who have done them. If early testing obviously saved lives, the people who sell testing would tout them everywhere. Instead, they're stuck trying to look for angles to argue that lessening death and suffering isn't the biggest consideration. They recently did this to push breast cancer screening earlier again, by arguing that if you specifically look at black American women, they benefit from early cancer screening. So overall, breast cancer deaths go up, but that's just your privilege talking. Woke conglomerates. Ignore that black people have a unique, neglected, discriminated against, and poverty-ridden situation in the US; in fact, it might even be racist to point that out (in backwards land.)

Of course, you definitely don't have to do the studies, plenty have been done. Anybody saying that they've looked and haven't found them has not looked or has seen them and is not telling the truth. Both positive and negative, about every test. The studies that support earlier and more testing are press released and marketed, though, while the others can be suppressed or simply ignored, unless some public health system or insurance company champions them, and of course they would.