> If the whole population had a full body scan every quarter, the “weird” things would feel more like the noise they are.

That's a tautology. We already have quite robust methods for detecting developed anomalies, treating every anomaly below standard human-to-human variation effectively raises the noise floor to already developed anomalies, defeating the purpose of population wide routine scans.

If you think the premise and conclusion of Op's statement form a tautology then you agree with him strongly.