Why isn't 11 pronounced "onety-one"

The romans could make numbers only upto twenty. After that they would just add one till twnety nine, then add one to nine after thirty and so on. As thet could make numbers upto twenty, there is no need to say onety one, onety two etc.

Similarly, in Hindi you have made numbers upto 100 after which you add one to ninety nine. Then similarly, after two hundred and so on.