There are specific examples for high prevalence conditions as you cite, but the original comment was not talking about that, it was talking about a broader appr

There are specific examples for high prevalence conditions as you cite, but the original comment was not talking about that, it was talking about a broader approach. Even taking your example, getting to the point of removing a pre-invasive adenocarcinoma is actually very complicated. You need a motivated patient, you need a healthcare team of specialist doctors or nurse practitioners, pathologists, radiologists, anaesthesiologists, nurses, an endoscopy suite, a recovery area, you need a system to follow up and track these cases etc. The full embedded cost of this undertaking is huge, I don't think it is scalable, and at the same time, will never capture everyone. Randomised studies usually just barely show that these screening approaches are better than not screening, once false positives are accounted for. Furthermore, you have chosen an example where there is a useful pre-screening test (fecal blood tests), a relatively non-invasive diagnostic test (colonoscopy) and a relatively painless intervention (removing a polyp with the scope). This is not broadly applicable. A pancreatic lesion for example is very hard to diagnose for sure, and the intervention is a massive and life changing operation.