Hi Sue,
You are right that the members who stay with this forum are largely those who have ongoing issues, so there are certainly those who do not need further treatment for quite a time if at all. One of the reasons why there is a greater risk of recurrence in the UK is that in many cases the PCa is not found early enough.
The jury is still out on whether RT it should be given early after Prostatectomy or later if rising PSA indicates the need, although there seems to be a move towards the former. However, there are cases where the surgeon, perhaps backed up by pathology, consider that in a given case early RT is advisable or can be reasonably left until such time as PSA and possibly further scans might show this could be beneficial.
As regards it possibly being considered barbaric to have treated PCa by surgery in the future, the same may be thought about radiation! There are a number of treatments being investigated including more advanced immunotherapy, http://www.dailymail.co.uk/health/article-5623197/Immunotherapy-treatment-game-changer-cancer.html
and alternatively one day men might just be vaccinated so they won't have this rotten disease, hopefully.
Meanwhile, whilst there is still a long way to go, men diagnosed recently have a greater chance of a better outcome, even with current treatment options.