No. Visual beauty is not a required element of landscape photography.

A lot of popular landscape work does emphasize dramatic, pleasing aesthetics, but that reflects one common style rather than a rule of the genre. There are established approaches to landscape photography that are much more neutral, documentary, or unsentimental. One example is the "New Topographics" movement, which photographed human-altered landscapes in a straightforward, non-romantic way—subjects could include ordinary built environments or even construction sites.

So the difference is less about one genre requiring beauty and another not, and more about photographers pursuing different interests, intentions, and audiences. Some landscape photographers seek grandeur or beauty; others are interested in evidence of human impact, structure, place, or observation. Street photographers likewise vary widely in what they value.

In short: landscape and street photography are not defined by a strict beauty vs. non-beauty divide. Both genres can be aesthetic, documentary, ironic, ordinary, or critical depending on the photographer’s goals.