From what I have read to me it just seems that the interests of the 13 colonies was no longer aligned with British

It rebellion is not legitimate but American has a population of over 300 million and the world strongest economy

And increasingly interferes in the UK

It's irrational but it seems they are afraid of the UK but in America history it was only ever threaten by three powers

The Mexicans, British and Russians

I would also say that their is the competition over the heart of the English speaking peoples which American is the winner