This is just not how math works, and it's why we still need doctors to order tests -- to protect people from themselves. You clearly don't know what you don't know, but you have a huge amount of confidence that you do, apparently.
Here's a list of different types of cancer screenings and where the risk/benefit falls: https://publichealth.jhu.edu/2023/balancing-the-benefits-and...
The risk of any cancer screening has to be calculated with variables like:
- how risky is the test?
- what are the risks of a false positive?
- how does a true negative affect the person's behavior in the future?
- what is the likelihood that the patient has asymptomatic cancer, based on risks like genetics and age?
- how difficult is the cancer to treat in different stages?
Without looking at all of those things, you don't know if the test is going to increase or decrease all-cause mortality risk.