If a website features many different options that are offered to visitors, such as a large amount of similar products or many small decisions at short time intervals. The result can be that the visitor is paralyzed by the choice (paradox of choice) and may get frustrated and unable to differentiate between the offered options.
To alleviate this issue, e-commerce sites that sell many different products use categories of products, display their most frequently bought or recommended products and use default values to minimize the visitor input. E-commerce sites that sell multiple styles for one product list that those items as one item and then let the customer pick which option they want.
If users are presented with too many options they will pick the easiest one which is leaving the site entirely. If your product has multiple options creating default options can help alleviate decision fatigue.