How did the giant planets help form the Oort cloud?

The Oort cloud is believed to have formed from icy planetesimals that accreted in the outer regions of the protoplanetary disk during the early history of the solar system.1

As the giant planets—Jupiter, Saturn, Uranus, and Neptune—formed, their immense gravitational influence played a critical role in shaping the distribution of these small, icy bodies. Specifically, billions of these planetesimals were gravitationally scattered or expelled from the vicinity of the giant planets toward the outermost reaches of the solar system.123

This process effectively relocated these icy objects into a vast, roughly spherical shell surrounding the Sun, which we now identify as the Oort cloud. While Neptune is often cited for its role in scattering these objects, the formation of the Oort cloud was a result of the collective gravitational interactions of the incipient giant planets as they cleared their surroundings of leftover debris.3124