> Superior how? Runtime costs? Sure, but it does beg the question how much. Will a well-optimized Svelte app feel much better than a well-optimized React app?
Virtual dom diffing is pure overhead. It increases the JS bundle size (react is big). Vdom diffing is really slow. And it's simply not necessary.
I agree that if you make heavy use of comparator functions, react apps can feel ok to use. But most sites don't do that. Look at the new reddit site. Insanely slow and insanely inefficient. They've improved it a lot since the new design landed. But it's still 19mb of javascript or something, and much slower than it should be. Maybe reddit is only slow because they're holding react wrong. But if everyone holds react wrong, it's react's fault.
If you don't like the asthetics of svelte, check out SolidJS. Solid is aesthetically almost identical to react. Solid - like react - only needs compilation if you're using jsx. The difference between solid and react is that solid only executes component functions once. Reactivity is implemented via fine-grained signals. Solidjs apps perform better, because there's no vdom. The default way to use solid is already fast.
> if something was truly dramatically better, then I think it would have a fair shake at beating out React.
Eh. Lots of old technologies are still in use. Most software engineers don't enjoy learning new frameworks every few years. And react still works fine, even if there are other options today. I think solid and svelte are better, but they might not be better enough to displace react for the average web developer.
If you like react, give solidjs a try. It's essentially "react with signals", which I find to be a significant improvement. You get much smaller JS bundles, better performance and better state management. All while keeping a lot of the best parts of react's design philosophy. It's great.