Before we get into extreme server side rendering (XSSR), we have to talk about normal server side rendering (SSR). This comes in two flavours, which I'm calling old-school and new-school.
Old-school SSR involves having a server which uses some logic to create the HTML of the web page on-the-fly. For example, you might hit /users/39, and it might give you the details of user 39. These details might be from a database, or they might come from somewhere else. The important part is there's no corresponding 39.html on the disk. The HTML is created dynamically by the back-end server. On the front-end side, there's no JavaScript or other logic required to render the page. As a result, once the page is loaded, there's no ability for it to be dynamic.
New-school SSR is similar to old-school SSR, but it does involve a bit of front-end JavaScript logic.
Lots of comments here saying it feels like work. And yet all the simulator games exist? People literally build rigs on their living room to play Truck Simulator games.
I don't work with rest apis enough and looks great. My only concern is that like everything I do, I end up building a UI and automation. Which might be the point!