My opinion is that almost everyone can see changes in his body on finasteride , be it sexual or not (body hair , belly fat , etc)
However they are usually mild , maybe some people wont even notice them . I assume the 1 % really needed dht for their sexual function , but probably more than 1% noticed changes but nothing important enough to report as a side effect
I was on Finasteride for 2 years between the ages of 17 and 19 and literally didn't have one side effect. I had an increased sex drive for like a week but after that I literally felt nothing.