alt Hacker NewsYou have a different definition of "being the product" than I do. A business that takes money from advertisers in exchange for your attention is selling your attention. You are the product is shorthand for your attention is the product, short of slavery.
But in order to fit the phrase the business has to actively fight for user attention to get the space for ads. This is specifically the search engine and social media model. Vivaldi is not fighting this fight. At all.