@jinxy Whether leg press is a better quad builder than squats comes down to body mechanics primarily. If you have short femurs and great ankle mobility, (& sufficient hip mobility), you can squat deep & induce tremendous tension on the quads & glutes respectively. Now lets say you have that - why leg press at all? Three reasons.
1) Injury related reasons, (i.e lower back, history of previous injury), self explanatory really.
2) Leg press better allows you to hit your quads in a higher rep range without cardio being a limiting factor, which has value.
3) Leg press is factually less systemically fatiguing. If 7 sets of quad work close to failure twice a week is damn near optimal for you but trying to do that all with squats crushes your CNS & ruins the rest of your workout, the leg press is the perfect complementary lift.
So, if you're not injured, can squat for high reps without gassing out & can hit your ideal quad volume with just squats, then you don't need to leg press at all. But if one of these variables doesn't make the cut, that's absolutely sufficient reason to leg press. And if your body mechanics aren't well suited for squats in the first place, then unless you have strength goals in the squat, I'd call that sufficient reason to not squat at all & to do other lifts, such as leg press.