manifest destiny

Manifest destiny is the belief that expansion is inevitable, justified, or divinely ordained.

The phrase originated in 19th-century American politics to describe westward territorial expansion as a God-given right.

Now used more broadly for any sense of entitled or inevitable dominance: Tech companies operate with a kind of manifest destiny, assuming they'll eventually control every industry. (Capitalized Manifest Destiny refers specifically to the 19th-century American doctrine.)