There are studies such as this where people report that spoilers increase enjoyment for narrative works.
According to research by UC San Diego psychology professor Nicholas Christenfeld, spoilers don’t ruin a story: They make you enjoy it even more.
My common sense tells me if the majority of people really held a consensus that spoilers improved people's enjoyment then we'd all just read plot summaries for every movie, tv show, comic etc. before experiencing them.
What is the scientific consensus, if any, on this matter?
Papers referenced in the article: