That doesn't make sense. If there's no space in behind or through the middle, you go around the sides, exactly what Sane does best. There's more than one way to skin a cat, the more options the better.
Liverpool use the fullbacks to provide the width, we haven't got the fullback to do that job (excluding maybe Cancelo and Angelino). Walker's crossing is atrocious, Mendy doesn't have the energy or stamina after his injuries and Zinchenko is not a fullback. Cancelo can't get Walker out of the team and Angelino isn't stable enough defensively to get in the team. Unless you replace 4/5 fullbacks, it's going to have to be the wingers providing the width.
Not sure what your struggling to make sense of here. When do you see teams NOT stick a back 9 in with a lone striker? How can you get through a box of 9? Its shown time and again that sane needs space to really prosper, the way we play in his current format he wont ever be that deadly player he has the ability to be. How many times do we try to go down the sides only to throw a hopeful ball in ? Livarpool get it in the box early generally on a break before teams are set. Teams that face us are set from kickoff! 9 -10 behind the ball!