The Krypton part of the origin is well known and has been done on the big screen by Donner and whatever that was Snyder did in 2013. What the general audience (that hasn't seen Smallville or read comics) doesn't know is Clark's travels after Smallville, his first adventures in Metropolis, and how he developed the Superman identity. They've also never seen a Superman at GA power levels and who works at the Daily Star and is a rival of Lois Lane. Krypton would be referenced in this film but would not be shown. There's a lot of other material in Superman's formative days to explore instead.