The fourth (optional?) fan is 80 mm and clips on to the back of the card. Also according to the article, its GeForce RTX 3090 SG featured a similar design. Before I clicked on the article, I had pictured a model with four fans on the front side.
Galax? What happened to the "y"? Sometimes it feels like I've been in a coma for years.
In my experience, fans have been the most failure prone part of video cards. Thus, when I buy a new card (which is not often), I pay special attention to the bearings used. I'm sure it's brand dependent, but I've noticed the higher tier cards are more likely to have better bearings than their low- to mid-range counterparts — not much of a shock there.