[xyzzy_plugh]

I'm curious -- what is not possible with just JavaScript? Why do you assume "a full-blown app inside a web browser" isn't possible without React or something like it?

Is client-side rendering strictly necessary? Do your websites actually run offline?

I've built websites with React, used React Native -- none of it is necessary, nor the end-all-be-all. There's nothing truly novel going on. You can accomplish the exact same experience with server-side rendering and a tiny smattering of vanilla JS (you can use modern JS and polyfills and webpack/esbuild without React, you know).

For 99.9% of the web, I'd argue you don't need it. I have yet to encounter the 0.1% personally.

If you don't believe me, know that I'm not alone. Take a look at https://levels.io/deviance/ -- PHP and jQuery. What would React provide that isn't possible with his stack?

There is a disturbing amount of kool-aid being consumed around React/Vue/etc. Sure, you can slap together a website in record time with massive boilerplate/templates -- but so can I.

[__s]

Here's your 0.1%: a card game, https://etg.dek.im before React I was using PIXI.js, over the years it's transitioned from being fully rendered in canvas to not using canvas at all (& now uses webpack, but years ago I had my own bundler mkcjs https://github.com/serprex/mkcjs which was pretty vanilla js, using require let me share code for awhile between server/client until server was rewritten in Rust)

react-motion made animating card transitions very straight forward

During a game you can click on history items to look at previous game states, this is very straight forward with React's model

Sure you could get this all by rolling your own state dom renderer, but that's like saying you can do everything Lisp does in C. Greenspun's tenth rule rephrased as "Any sufficiently complicated JavaScript UI contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of React."