No need to push anything. Distances between objects (that are sufficiently far away from each other) just increase as if there’s "more space" inserted between t

No need to push anything. Distances between objects (that are sufficiently far away from each other) just increase as if there’s "more space" inserted between them in some sense. There’s the concept of spacetime metric, a function that’s sort of a universal measuring stick for distances in the universe, and it is "shrinking" (as in there’s a parameter that varies as a function of time) so that a distance that used to be three measuring sticks long is now three point one.