The question is how can you know if it needs treatment or not. I guess you either need to do a biopsy, or check if it's grown after N months (leaving patient scared and anxious during that time). Neither are great if most cases end up not needing treatment.
If the test provides you zero information about whether it needs treating then it was never a useful test. Presumably it's more like "there's a X% chance this needs treatment". In which case you just set reasonable thresholds for X. E.g. if it's 5% you monitor it, 10% you do a biopsy, 70% you operate, etc.
This is much more sensible than just not testing at all and letting people die from cancer.
> leaving patient scared and anxious during that time
This seems to be the actual motivation. We don't want to scare people with test results so we're just not going to test them. I think that should be up to the patient.
> This is much more sensible than just not testing at all and letting people die from cancer.
This is not what happens. You're assuming that if the cancer does not get detected by the screening then it never gets detected. What actually happens is that the test gives information that might actually be redundant and obtainable in less risky way. What the studies are showing is that waiting until there are other, more specific signs and symptoms of the prostate cancer results in the same survival rates.
See https://pubmed.ncbi.nlm.nih.gov/38926075/. I was not aware of the ERSPC which came out late last year and gives better outcomes for screening, but overall the evidence is not super clear yet. There are possibly certain groups that can benefit from PSA screening more than others. Also, modern, more effective treatments might allow for later diagnosis with the same clinical results.