This is where skill and experience come in. Should huge wizards and complex forms be constantly sent back to the server and rendered as each bit is filled in?

This is where skill and experience come in. Should huge wizards and complex forms be constantly sent back to the server and rendered as each bit is filled in? Of course not. But if you have a basic CRUD app with a big dashboard, create route, edit route, view route, etc., it's a hell of a lot cleaner to break up each one of these main features into mini SPAs that cleanly refresh the state on the server when moving from one function to another. Otherwise, you're constantly making duplicate calls to ensure you've got the data you want as you really can't be sure if some previous click from one of dozens of in-memory widgets has stale or incomplete data. At least that's been my experience working on a few legacy apps written in AngularJS and, God forbid, JQuery. At that time, an Asp.Net or GWT app would have probably been easier to maintain as the duct tape increased over the years. Maybe React and Vue allow for cleaner architectures, but older apps were a pain.