I have a simple question. We know pulling a lawn roller at an angle is easier than pushing. It's because when we push a object with a force $F$ at an angle $θ$, the weight of the object becomes ($mg+F\sin θ$) which gives more friction. And when we pull, the weight becomes ($mg-F\sin θ$) which results in less friction.
My question is: Is pulling still easier if we are on a frictionless surface?
If you are on a frictionless surface, then when you are pulling there will be no force opposing your pull. We now want to maximize the force that is pulling in the horizontal direction. Suppose that you are pulling at an angle $\theta$ with respect to the ground.
This means that the force pulling in the $x$ direction is $$ F_x = F\cos\theta. $$
In order to maximize this, we want to set $\theta =0$, so $\cos\theta = 1$. This means that you would not be wasting any force in the $y$ direction.
Putting this together, the pulling becomes "easier" (in that you don't waste force pulling in the $y$ direction) by making the angle with respect to the ground as small as possible.
Of course, note that without friction pulling at all would be easy, it just becomes a question of how much you accelerate depending on the inserted force
Edit: I realize your question is pulling easier than pushing, without friction they would be equal as you are not losing any force to friction, its purely defined by your angle of application