SPA frameworks query the server for JSON and then render HTML right?
Simpler in the sense of what? You prefer to not have all of the variables available when you render HTML? It's simpler to only render client side HTML and to query 4 different AJAX endpoints for resources?
Why are you trying to separate business and interface logic? Why are you displaying anything that the business logic doesn't understand?
The entire point of good code is that I can edit 1 file instead of editing 3.
Back end frameworks don't help you organize code? That's kind of their point?
Modern SPA frameworks (-> next.js) offer a similar 1 file code style and require no (manually written) api routes.
The end result looks very similar to the server side frameworks of old, so it's a bit of a circular evolution. I think only using one programming language (the one that is part of the web platform) and a solid, template free component framework make it incrementally better though.
SPA frameworks query the server for JSON and then render HTML right?
Simpler in the sense of what? You prefer to not have all of the variables available when you render HTML? It's simpler to only render client side HTML and to query 4 different AJAX endpoints for resources?
Why are you trying to separate business and interface logic? Why are you displaying anything that the business logic doesn't understand?
The entire point of good code is that I can edit 1 file instead of editing 3.
Back end frameworks don't help you organize code? That's kind of their point?