Raiders of the Lost Ark is now considered a classic, but before it was released, many people didn't believe that the first Indiana Jones movie would work. Raiders of the Lost Ark is an incredibly exciting throwback to adventure serials of George Lucas and Steven Spielberg's childhoods, with the film launching a franchise that has surpassed these inspirations in nearly every way. However, this almost didn't happen, as a lack of faith in the original Indiana Jones movie meant that Raiders of the Lost Ark almost didn't happen.
https://screenrant.com/indiana-jones-raiders-lost-arc-people-didnt-believe/