Or forest, anything with trees. A flat forest like most of Finland has very limited visibility, the only time you can see far there AIR is when standing at the edge of a large lake.
But the default temperate terrain is forest though, so this is a major point.
I grew up in New England, which has been called the world's most successful reforestation experiment, and specifically in New Hampshire, which recently became the most forested state in the USA. It's forested and hilly.
Hills are only good if they're bald. A forested hill is crap for views, and you cannot get high enough in a tree to be higher than the other trees.
In temperate forest in general your view is cut to significantly less - 100 yards would be a great view. I imagine the situation is much worse in a rainforest (either temperate or tropical).
Furthermore, range of vision does not confer detail perception. I can stand on a mountain peak and see my father's house (about 4 miles as the crow flies), but vehicles are tiny dots, and people are impossible. Most structures are recognizable from the shape of the fields around them, not the buildings.
So, can a human see "the entirety" of every 2-mile hex around the hex they are in? IMO, only in very broad strokes, and under specific conditions. Flat terrain, with no growth above waist-height. Nothing under 15' - 20' is discernable. No details.