First NIH said it does: https://www.nih.gov/news-events/nih-research-matters/viagra-... Then it doesn't: https://www.nih.gov/news-events/news-releases/nih-dream-stud... Then it does: https://www.ox.ac.uk/news/2024-06-07-sildenafil-viagra-impro... Who knows what to believe.
This may be a sincere statement, but I'm not sure it's a helpful one. What data do we have? A 2:1 advantage in published studies that it does help. Since there is no such thing in science as absolute proof of anything, these are pretty good odds. Certainly more work will be done in the future to try to replicate the results and figure out the one negative outcome. But until then, we cannot say that the evidence is in any way "equal" on both sides.