Why is the law of conservation of linear momentum a universal and fundamental law?

(N/A) The law of conservation of linear momentum states that if the net external force acting on a system is zero,the total linear momentum of the system remains constant.
$1$. It is considered a fundamental law because it is derived from the homogeneity of space,meaning the laws of physics are invariant under spatial translation (Noether's Theorem).
$2$. It is universal because it holds true across all scales,from subatomic particles in quantum mechanics to macroscopic objects in classical mechanics,and even in relativistic scenarios where mass varies with velocity.
$3$. It does not depend on the specific nature of the forces involved (whether gravitational,electromagnetic,or nuclear),making it applicable to all physical interactions.