It makes them visually stunning. That is the purpose.

High contrast also makes tiny colorful details easier to see.

The photos are absolutely gorgeous, and it looks like whoever's taking them has some seriously expensive glass. I'm guessing that someone in charge wanted the photos to "pop" and the contrast got boosted just slightly too much. In my opinion it doesn't ruin the photos, and it's only really visible in a handful of them.

I think there's something else going on in these pictures. Some of them appear in focus over the whole image (large depth of field), which makes them look a bit synthetic.

I wonder if they're composite images, or just using some great lenses.