Why did Britons made the most important and greatest rock music?

[Smaug]

Didn't Americans invent rock&roll?

Not in my book.

[Dna8]

I'm no music historian, but maybe there was something of a Greco-Roman esque dynamic, with Americans initiating, Brits adding structure and formalizing..

However, as goes the proliferation of genres and subcultures, say, late 1970s onward, America was most influential?