Why is Adam Smith considered the “father” of modern economics?

Hi folks,

I'm getting back into economics, and have read the sentence I'm sure you all have read. "Adam Smith is considered the father of modern economics". I understand Adam Smith's contribution to formalizing economic concepts with "A Wealth of Nations" and the Invisible Hand. But it's not clear to me what made his contributions be considered the "start"? "A Wealth of Nations" was published in 1776, centuries into Europe's colonial expansion. And there are at least several millennia of nations and empires running large economies.

Was there not a formal concept of economics before then? And if not, was there any prevailing understanding on markets before then? For any experts, where could I read to get an understanding of the "pre-history"

The core of my question is – what made Adam Smith's findings a revelation to the world of that time?