Yes but the difference between EM and gravity is that diamagnetism repels, so the closer two objects get, the more force it requires to bring them closer, ultimately approaching infinite energy. Gravity is attractive so it takes less energy the closer two objects get, it would approach infinite energy to stop further gravitational motion. So gravity can easily dominate EM at Planck scales.

idk about the strong and weak forces because frankly I have absolutely no idea how they work. EM is largely magical to me still, though it's easier to somewhat understand. Gravity is the easy one, at least at macro scales.