We don't get a representative sample of treatments and side effects on this forum, or any other support group. Remember in the UK about 40,000 men per year are being diagnosed. For some the disease is insignificant, they will die of something else, for others it is too late for treatment. I would guess about 20,000 get some form of radical treatment in the year. On this forum we see perhaps a thousand people a year. So 95% of people being treated in the UK we don't really know what's going on, they may be very happy with their treatment or very sad. The medics do follow up patients, so if something dreadful was going wrong we would probably hear about it. So I'm going to have to guess that at least 95% off people are happy with their treatment and just get on with their lives.
If one is looking for the best chance of 'cure' for a T1 or T2 it is almost certainly prostatectomy. And for a T3 it is almost certainly RT(HT).
Now if you're only interest in 'cure' as an outcome, you could start thinking 'out side the box', why not remove the penis, testicles and lower bowel, just in case, or RT the entire body and castrate instead of HT. The answer of course is side effects. We are looking for a cure, but only within acceptable side effects.
When you add in side effects, the remaining life expectancy becomes very important (we only need the 'cure' to last a few years). The severity of side effects, e.g. incontinence, is severe, but the probability is not too high (remember about 95% of people are not complaining). The factors in knowing the best treatment are complicated, and no-one knows what they all are when they have to make a choice.
When people are first diagnosed with cancer and come on this forum, they are trying to avoid death, their focus is often on the most aggressive treatment. I try and make posts to remind them they will never avoid death, at best they can postpone it, and that they just have to live the best life they can until the grim reaper arrives.