Good point and that is why we are stuck between a rock and a hard place when advice about quitting is requested here.
With the many post drug patients who say they took finasteride or antidepressants with either no noticeable side effects, or only mild side effects, only to go on to crash horribly within weeks of stopping; it makes one wonder if the better answer is to keep taking the drug. It seems it obviously would have been in your case.
The problem is that all drug classes here have been shown to have effects that can be easily interpreted as detrimental to health over time. (e.g.: rodent studies showing fin decreases neurosteroids regardless of PFS and negatively impacts sexual organs and function, and studies showing SSRIs reduce hormone levels and may exacerbate atherosclerosis.)
Should a person risk potential health problems by staying on the drug to avoid an unknown, but presumably small, chance of developing PFS? Will they be unable to have access to the drug at some point for some reason? (At least one story of a member here crashing from fin while traveling and unable to fill his prescription.) Others began developing symptoms, apparently out-of-the-blue, years into treatment. If they stopped sooner, would they still have developed PFS? Who knows.
There’s also no evidence suggesting less time on the drug = less chance of getting PFS.
Or that the odds increase as time goes on…
Only sure bet is to not take one of these drugs in the first place, but I personally would err on the side of stopping one way or another, given the choice. Because everything points to a much greater chance of a person not developing PFS if/when they quit.