Very true, but in an l evolving application you often pay the cost of that approach because any small change to the data displayed or the behavior of the application will require a change to both frontend and backend (e.g. wiring up a new API), so in practice I think people tend to build in a certain amount of generality. It's a kind of trade-off between the time to design a more general API vs. the time to churn the existing API when we tweak the application.