one, the article is 14 years old. two, the point of ambient occlusion was not about making geometry look good, it was about making lighting look good.

The main issue it solved was normal lighting at odds with the world, it was for fast general approximation of global illumination.

I think the prime example of SSAO being helpful was Fallout 3. FO3 has very simplistic lighting even for its time, kind of looking like "fullbright"/non-shaded mode in Source engine. SSAO, when it was added as a graphics driver feature, suddenly gave interiors depth that they were severely lacking, and while it didn't always look "realistic", it almost always looked much better than without.

Another point of context: at the time, several popular games had used a very exaggerated and/or poorly implemented ambient occlusion feature. I personally would frequently turn it off entirely because it was generally expensive (even if not as expensive as full global illumination) and looked bad.