Why was Marbury v. Madison significant to anyone outside of William Marbury's immediate family?

Marbury v Madison (1803) is arguably the most important legal case in American judicial history. Why? Because the case established the principle of judicial review, the power of the United States Supreme Court and other federal courts to strike down acts of Congress which they deem unconstitutional.
The principle of judicial review is of immense importance in the development of the Supreme Court as one of the three branches of federal government. Marbury vs. Madison gave life to the philosophy of the Founding Fathers that governments should be of laws, not men. Who is it that interprets the law? It should not be politicians (who make the law), but judges. A Constitution made by "We, the People" then becomes a document whose meaning is decided by "We, the Judges."
To that end, the case enshrined the principle that the Supreme Court has the right to determine what is, or is not, constitutional. That right has been jealously guarded by the Court ever since and passionately debated by friend and foe alike. Marbury vs. Madison has been such a contentious case because the Constitution is both a political and a judicial document. This raises the question of precisely who should be charged with its interpretation. Should it be democratically-elected representatives, even if they lack appropriate judicial training? Should it be legally-qualified judges, even though they are not elected and are therefore not subject to democratic control or recall?
The debate continues.
https://www.thoughtco.com/marbury-v-madison-104792