The answer involves several factors, the main one in my opinion is the visual, as I always say a website should be like an advertisement for a Porsche in a magazine, “you are not going to turn the page without looking at it.”
Consider that 83% of human learning occurs through visual stimuli, in this sense, images play a very important role in the development of the website. These must be real and of good resolution.
Another important variable is the ease with which the person visiting the website finds the information they need, if the user finds it difficult to find what they are looking for, they will simply go and look elsewhere (probably their competitor).
It is said that content is king, I do not consider it to be the monarch of the web, but it is very important for both users, finding good content that meets their needs as it is for the search engine. Google tends to reward those websites that offer content that generates value for users.
Many of us are not interested in web programming, SEO techniques or web usability, I don’t think it is necessary either! For this there are programmers, designers, SEO consultants, analytics experts and other specialized professionals. Which does not exempt us from the responsibility of supervising the development of a website, which in a few words must be friendly and attractive.
Ah! Mobile First!
You can see my consulting service of Digital Strategy