Link to the page is perceived as a guarantee of its value. The number and quality of links to a website is a kind of recommendation/signal for Google, Bing, etc. algorithms.
The more such signals, especially from large portals, the better the visibility of the page in the search engine. The situation is similar with the citation of a scientific paper – the more articles refer to it, the better.
Website promotion in a search engine allows you to attract more referral traffic, increase brand/offer/product awareness among potential customers.