What is the fundamental physics challenge preventing electric rockets from powering liftoff from Earth?

Answer

They cannot provide the overwhelming, instantaneous thrust needed to escape Earth's gravity.

Chemical rockets succeed due to the brute force of instantaneous thrust created by burning fuel. Electric propulsion provides a gentle, continuous push which is insufficient to overcome Earth's massive gravitational pull from the launchpad.

What is the fundamental physics challenge preventing electric rockets from powering liftoff from Earth?
physicsspace travelrocketspropulsionelectric propulsion