Genuinely confused about timing and extent of PSA screening.

I must admit I am really confused about prostate cancer screening. I guess I am excited that there is the PSA blood test but don’t understand who should take it at what age and whether it’s sufficient.

In particular, how did Joe Biden end up with advanced cancer? I read somewhere that he stopped screening? Why?

https://www.npr.org/2025/05/19/nx-s1-5403446/biden-metastatic-prostate-cancer-diagnosis-survival-rate

And in the other side it seems Ben Stiller got lucky that he got a test earlier than normally indicated (since he had no risk factors).

https://www.healthcentral.com/slideshow/famous-men-who-beat-prostate-cancer-or-caught-it-just-in-time

Why is this so confusing and why can’t we have a clear guideline accepted by doctors and insurance to have clarity?