There isn’t a non hybrid version of the Prius with all its weight and aerodynamic features.
But there’s ~45 MPG all gas cars that have been built. Currently the best option is 39MPG combined, but that car’s aerodynamics aren’t great because hybrids can push that a little further for people who really want maximum MPG.
Combined mileage from many hybrid power trains is only ~10% better, and the technology inherently adds significant costs/complexity.