I was joking. I usually hear complaints about SPAs from backend engineers who see frontend as a few server-side rendered forms with some validations thrown in. An equivalent to that is a back-end with a thin layer atop of database tables. I programmed server-side web forms in ASP.NET and JSP for years before switching to SPAs and React. Literally everything is better with React. Everything.
You do need an HTTP server if you want to offer an HTTP service.
> Heck, why don't we just let the users get what they want by giving them access to a SQL prompt.
I don't think any RDBMS has a sufficiently complex permissions system to accommodate the needs of a webapp.
> We could eliminate the UI completely.
Obviously, any user needs a UI to interact with any software, so I'm not sure what you're trying to say here. Your proposed SQL prompt is also a UI.
I feel you're trying to imply something here, but I'm at a loss as to what that is.