> No one can convince me that detecting cancer earlier isn’t, on average, a good thing.

Since no one can convince you, indeed you should not bother to read any of the extensive literature on the subject.

But consider that if indeed it does not extend lifespan, but does extend treatment span, patients will suffer a worse quality of life on painful treatment that does not help and the concomitant fear.

A shame, because you finger health care expense and this phenomenon increases health care expense.