This always feels like a thinly veiled excuse to ration healthcare. Would these same doctors refuse a full body MRI to a billionaire paying out of pocket?

Anything found can be monitored with focused follow up scans. It doesn't have to be immediately biopsied if it's in a location where that would pose a risk of iatrogenic harm.

At a population level, this would be both extremely time-consuming, and rather expensive.

More generally, no test is perfectly accurate, and for low base rate conditions the vast majority of positive tests will be false positives.

Like, again, as a data person I adore this idea in principle, but there would be a lot of details that we'd need to figure out to make it a reality.