Please don't co-opt the word "production" to mean what you're implying here. Production doesn't mean single-page, reactive, etc. applications, it just means "in production."
Source: Running "just JS" in production for more than 6 years.
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.
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."
This is the tell. If you are able to satisfy your business requirements with "just JavaScript" then you are in a completely different world than the people building production-grade web apps and there's absolutely nothing wrong with that. If you can be productive with "just JavaScript" then that's awesome!
However, I'm sure you understand there's a massive difference between simple pages that need *some* interactivity and a full-blown app inside a web browser.
I'm sure you've come across projects that probably didn't need the same tooling that I'm describing which ultimately boils down to a judgement call.
> I've never been like "boy I really need a virtual DOM" so I guess I've never really seen the appeal of React. It just seems like a bundle of complexity, obfuscation and anti-patterns.
That's because you've never needed it before. I've never been like "boy I really need a batteries-included web framework" so I guess I've never really seen the appeal of Rails. It just seems like a bundle of complexity, obfuscation and anti-patterns.