“We never consented to be subjects of the King.”
That’s not an argument that the American founders made. It’s an objection invented in recent times that gets repeated as if it were something that they believed.
The founders were born subjects of the Crown. And as they say in their 1774 Petition and the 1775 Olive Branch Proclamation they remained loyal subjects. They simply wanted their rights as British subjects respected by London.
That was the root of their grievance. Russell Kirk wrote about this in his argument that the American Revolution was conservative in nature.
They were demanding their Rights as Englishmen. You are no longer a subject when they are not protected as the sovereign
is required to do, you are just a slave.
Our Founders were opposed to slavery particularly when they were the slaves.