While the higher frequencies (shorter wavelengthS) dont penetrate as well, they’re less likely to be impacted by obstructions because of narrower fresnel zones.

In other words, you don’t need your antennas to be as tall to get around curvature of earth (or that building in the way) with higher frequencies.

So one tall tower and a bunch of receivers on the ground in the desert: 5.8ghz is probably a better choice than 2.4.

Of course there are other factors.