How does the lower power requirement for LEO satellite signals benefit the spacecraft itself?

Smaller power requirements allow the spacecraft to be physically smaller and lighter

Because LEO satellites are positioned much closer to the ground terminals than GEO satellites, the signal strength required to establish a reliable link is substantially reduced. This decreased need for high transmission power directly translates into benefits for the spacecraft design. Smaller power requirements mean that the onboard equipment, including power generation and transmission components, can be physically minimized. This reduction in mass and volume leads to satellites that are physically smaller and lighter, which in turn significantly decreases the associated complexity and overall cost involved in launching them into orbit, facilitating the deployment of massive constellations.