It's not obvious from that what the difference between React and Next.js is. React handles rendering UI components, you don't need either to fetch data from APIs, and displaying images and fonts is not something you need any JavaScript for, and srcset and media queries deal with optimizing, still no JavaScript required.

I'm not dismissing Next.js or you, I just feel like these aren't great points in a vacuum.

Next adds all the "missing pieces" that you would otherwise need to cobble together yourself when using just plain React to create a production-grade and ready web app.

Obviously these things can be done without using Next, React or even Javascript, like you say, but it all comes in a really well-integrated solution that mostly just works.

I could believe it, I just think it's hard to sell that to some people, as it's not very specific. The pitch just isn't that compelling, as things like "fast", "just works", etc. aren't very useful. I'm not against things like Next, and I do think they're useful, but this branch of discussion was about the pitch. The homepage lists "Client and Server Rendering", "Nested Layouts", "Data Fetching", "API Routes", "Middleware", and "CSS Support" (and a few others) in a list of features that "make the web. Faster." Other than middleware, I would sure hope all of those things would be supported by a web tool since they've all been features of web browsers and servers for decades.

The point is that it's not clear what exactly Next does, let alone why it does those things. In my mind, Next (and friends) just helps smooth the edges of all aspects of modern web development. That's just not a very specific statement. Also, a lot of those edges aren't so sharp for a lot of use cases since modern browsers and servers offer the same functionality. I still think Next and friends are useful because the edges may not be as sharp, but there are quite a lot of them.