A single-page app is almost always worse than a multi-page app
So, the OP argues that SPAs introduce unnecessary frontend state:"I think this is a very underappreciated aspect of SPAs. Stateful software is always more difficult to work with than stateless. The frontend state is added on top of the already-existing backed state. This requires more development time, increases the risk of bugs, and makes troubleshooting more difficult."But the thing is, almost as soon as you have any kind of significant user input to handle (multipart forms, date pickers, autocomplete elements, conditional input elements) you are instantly dealing with complex frontend state. And then your choice is not "SPA vs plain HTML forms," it becomes "SPA vs (ad hoc jQuery tangle + ad hoc server side endpoints that know to speak to random jQuery UI libraries)."I find the ad hoc jQuery+endpoint tangle much harder to reason about than something built with a front end framework and a more uniform API.