I meant that what would've become the US will be something similar to Canada or Australia. I just worded it funny.
For the past at LEAST century, America has been the greatest nation on the planet. Canada and Australia are jokes compared to America, even now in America's twilight years. They still are peons compared to this country.
Because of population. Canada is physically larger than the United States. Australia is the same size as the continental United States. But where the United States population is 330 million, Canada's population is 37 million and Australia's is 25 million.
Australia and Canada cannot support large populations because it is too hot and dry over here, and too cold over there, for them to be suitable for large scale human habitation.
Now here's the thing about post-industrial power, population plays a huge role. You need lots of people to build up an economy. You need lots of people to procure raw materials, you need lots of people to manufacture from raw materials. And that's how you get the navy and the air force and the army kitted out. Endless production resources.
The United States did not become a great power by accident or by luck, but because it happens to be a very suitable land to support a huge population, and that land is basically immune from being invaded ever because its protected by two giant oceans along the eastern and western borders, while to the north and south are countries that cannot even come close to matching American population and therefore American production and American militarization. Canada and Australia are also fantastically protected naturally by oceans, but they never grew like the United States because it's physically impossible for them to do so. Australia is already over-populated with just 25 million!
So the reason Australia and Canada turned out the way they did has nothing to do with the question of independence from Britain. So too does the question of what would have happened to the US if 1776 hadn't been a thing.
Suppose the 13 Colonies stayed loyal to Britain until they were eventually granted a peaceful independence at the start of the 20th century. I still think by the end of that century that the US would have surpassed the UK. The UK relied on its colonies in Africa and south Asia to supply the raw materials and the mass labour force required to industrialize and militarize. But they're so far away from home, plus the people there don't like you, and on top of that you're destroying them by, for instance in India, forcing them to grow cotton and opium instead of rice and wheat, without which there was repeated famine and huge incidents of mass death. So the problems for the UK are that the supply chain is vulnerable because it's so long, that the labour force doesn't like you, and that your continued exploitation of that labour force is actually killing them.
Contrast this with the US. The supply chain is small and compact - it's all within your own borders. It's safe. Secure. Bulletproof and foolproof. If you need a shipment of iron ore from a mine in New York to a factory in California, it's no problem at all to make that delivery. On top of that, because its their homeland and their people responsible for every step of the way - acquiring raw materials, manufacturing them, and then building military infrastructure - your government is forced to take into account the need to keep those lands in decent condition, to keep the people alive, and to keep them content with the way they are treated. So they can't turn the place into a wasteland like the British did, they're forced to take a more sustainable approach to industrialisation.
Once the African and south Asian colonies were lost to them, the British were fukked because they didn't have access to raw materials or to vast manpower reserves anymore.
But for the US, because everything is domestically sourced, becoming a great power was an inevitable outcome. Independence from Britain perhaps accelerated the process, so that by 1919 the US was the leading power in the world. It might have taken until 1969 in our alternative timeline where 1776 never happened, but it was still destined to happen.