It depends on your type of product. Landing pages that advertise products that are visually pleasing and self-explanatory can afford to rely more on visuals than text. For example, by using photos of the product in different setups, close-ups and side-profile shots, the target audience will get a good overview of the product and its different features, without having to read a lot of text. At the end of the day, too much text can make a landing page less interesting and harder to digest.