dxc6 it's a multi prospect move. First mainten the pressure blacks Queen has on the f file, second it open the diagonal to light square bishop getting development. What black do here with dxc6 calls : earn tempo.
In order white to complete development, soon will offer a Queen trade. After that long castling is a good option because the Quenn side rook will be placed automatically in a open file.
Why is dxc6 recommended doubling the pawns instead of taking with the queen? Only reason I can see is to castle queen side but why is castling queen side good in this opening?