We give blood glucose level tests and cholesterol tests to everyone every year at the physical because they are cheap and easy to administer. Even though the effects of both may take decades to have any effect and have no correlation to ultimate death. It’s about trade off of cost and convenience.
If you detect pancreatic or colon cancer in a 20 year old patient via $1 blood test, that is immediately actionable. Cancer is ALWAYS actionable unless you’re talking about prostrate which grows slowly. But even in a 20 year old, you would want to treat that but maybe not a 70 year old.
And we’ve never had the ability to detect stage 1 cancer of the deadliest types of cancer. Imagine the new treatments that might save lives if we could.
Honestly, the number of people here who think they know better and citing unrelated research is bordering on anti-maskers parroting the surgeon general saying masks don’t work when they do.