I guess it just depends on the definition of "totally." It is very much possible to develop something based on the insights from Newtonian physics for example. Newtonian physics is flawed, but often good enough.
Right. Newtonian physics is an example of a good enough theory. Although it's been proven "wrong", it's still taught in schools and will suffice to get a rocket from Florida to Mare Tranquillitatis. No mean feat.