Once you move beyond basic CRUD business requirements work their way into the UI. For instance, making fields read-only based on access level. Adding additional

Once you move beyond basic CRUD business requirements work their way into the UI. For instance, making fields read-only based on access level. Adding additional form fields, etc. Conditionally hiding and showing entire portions of the UI. All of which requires you to either pass around UI-directives in your data or implement business logic in your client code. Better to just ship HTML, and if we're worried about full page loads, just use one of the many over-the-wire options to only change small bits of a page. This is before we get into having to implement application primitives like authentication on the client, and all of the state management that goes with. The absolute amount of scaffolding and plumbing we've built up just to save a few ms is always worth questioning. Doesn't mean the answer is no, just that we need to ask the question and not assume the default is carved in stone.