On the other hand, it saves a lot of time in backend development if all you have there is an API. HTML rendering, form handling, etc take up a lot of time in t

On the other hand, it saves a lot of time in backend development if all you have there is an API. HTML rendering, form handling, etc take up a lot of time in the backend too. And with the interactivity that is expected now for many pages (forms just as an example), you end up having to duplicate a lot of things on backend end frontend. And you end up using a framework on the backend too, because you really don't want to hand roll all the routing, templating and form handling. You don't. Trust me. As long as you are comfortable with a JS stack (or have specialized devs for that) and have a good way of server side rendering figured out, I don't think an SPA incurs a big overall tax. As an additional plus, there can be a lot more decoupling between frontend and backend work. You can stub out the API and work on the frontend independently in a much cleaner fashion.