Here's one issue I see with American law... which is that the (US) government has, in the past, passed laws (such as the Sedition Laws) and it takes a long time

Here's one issue I see with American law... which is that the (US) government has, in the past, passed laws (such as the Sedition Laws) and it takes a long time for those cases to get to the Supreme Court, so if the government wants to curtail speech arbitrarily (albeit temporarily) they can.