Traditional launch escape systems protect only a fraction of ascent.
They create a hard failure mode: if the tower fails to jettison, the crew dies. Most are discarded after second-stage ignition and offer zero protection on return, the Moon, or Mars.
Starship discards the architecture entirely. Engine-out redundancy is designed so that losing one or several engines is non-events. The vehicle itself must be safe enough for crew without an escape system.
Anything less makes Moon and Mars flight impossible.
Fly the system until the vehicle is the escape.
Source I
@Erdayastronaut