This is also why 2D jump platformers like Megaman have triangular jump trajectories instead of parabolic trajectories. For snappy controls you leave the ground at the instant of the downpress and peak when you let go of the button. As the game can't know how high you intended to jump at the time the jump begins, the trajectory can't be parabolic. (At least, not on the way up.)

You could instead have the button downpress "charge up" energy and then begin the jump when the button press ends, which would allow for more realism, but also introduce a delay.