Actually, some of the research papers put the risks of PVPS rather higher than 10%, but I've quoted that figure as it's the one the NHS publishes.
Severely affected men (ie those where the level of pain has lasted over 3 months and prevents sex or interferes with the quality of day to day life) cannot necessarily be treated and the condition becomes long term.
If only mildly affected, conservative measures such as scrotal support, heat or cold therapy, and anti-inflammatory medications can be tried. Not fun to live with aching balls all the time for years, but not classed as 'severe'.
But for the severe cases further surgical treatment is all that remains eg microsurgical denervation of the spermatic cord, vasovasostomy, epididymectomy, and inguinal orchiectomy. Vasovasostomy (vasectomy reversal) is an effective intervention for some.
There are fairly serious complications such as like granulomas and haemotomas as well, but they are treatable.
There are no reliable indicators to predict which men will get complications, and of course for 90% of men it's fine and they are back to their normal selves in a month or so (can be much less). But 10% won't, and if a man does not want to undergo a procedure with that level of risk attached, that is his choice and it needs to be respected.