I feel like Marvel could have set a new trend of not even having a trailer and just dropping a due date. However they did the complete opposite and just show everything and its not just Marvel but I use them as prime example because of Civil War. They could have kept Spiderman a secret, hell they could have kept Black Panther a secret for that film but nah they blew it. If I were Marve I would have dropped Civil War, Black Panther, Infinity War, and Endgame without trailers.