Is it not generating HTML on the server to be served to the client? What you're describing is, in my opinion, an overly complicated form of dynamically rendering HTML on the backend. It's exactly what I'm talking about: the layers and layers of complexity modern web development has added hasn't really solved any problems but rather primarily created problems which are solved with another layer on top as a fix which has problems of its own, and repeat.
Anyway, that's my opinion on the matter, I've toiled with modern web development tools my fair share and time and time again found that removing all of them in favor of vanilla JS where strictly needed and traditional dynamic backends is the most reliable and performant, and frankly enjoyable form of web development. I know others like those workflows and the complexity/power they bring and that's fine, it's not my cup of tea though.