This isn't true, if the American revolution hadn't happened then those slaves would have been freed peacefully already by 1833:
https://en.wikipedia.org/wiki/Slavery_Abolition_Act_1833
Or maybe that would have triggered an American revolution again because Americans love their slaves, I mean it happened that way as is...
But the UK still continued to buy US cotton, knowing full well it was enabling the slave trade to continue.
And the most important point was they had setup all of these colonies with these systems in the first place.
> we were the colony to finally collapse the system after many centuries of it being standard across the world.
That is blatantly false. That was my point. You are right the Europeans weren't angels, but you were absolutely wrong there, America was the colony that was dragged kicking and screaming to abolish slavery long after everyone else had already done so, it absolutely wasn't the colony that finally collapsed the system of slavery it was pushed by everyone else to end it and then still had to go through a civil war doing it.
The UK even continued slavery in Indian colonies until 1843. They only abolished sugar plantations because it was not profitable anymore.
If the American colonies didn't rebel from the UK, they may have not abolished the cotton plantations themselves because they highly depended on it.