George was a pirate, but he wasn’t a very good pirate.
During the American Revolutionary War, he obtained letters of marque from both the colonists and the British Empire, and he stole from pretty much everyone.
When he raided ships leaving England for the Americas, they had a lot of soldiers, weapons, and ammunition.
Those raids didn’t end well.
So, he preferred to raid ships leaving the Americas for England. The soldiers tended to be tired or wounded, and easier to defeat.
Their cargo was worthless: barrels with the preserved bodies of the dead, heading home for a proper burial.