... but the whole social movement of "back to the backend" is about getting rid of the client-side application as a separate component
of course it (should) lead to a lot less code! at the cost of completely foregoing most of the capabilities offered by having a well-defined API and a separate client-side application
... and of course this is happening as over the last ~2 decades we mostly figured out that most of that amazing freedom on the client-side does not worth it
... most clients are dumb devices (crawlers), most "interactions" are primitive read-only ones, and having a fast and simple site is a virtue (or at least it makes economic sense to shunt almost all complexity to the server-side, as we have fast and very capable PoPs close to users)