When it is text, it's usually more small bits of text than big bits. If you're just copying around giant strings you're unlikely to be using webasm. More likely you're copying around tons of small strings as you format them into a giant string if that's the end goal. Or you're copying around tons of small strings as you use those small strings to make api calls to the dom (indirectly through js). Or you're just plain running something like a physics simulation and don't even have text in the first place.