While I like Svelte, I fear it looses some of the flexible API-building enabled by React.

Specifically: since it uses a templating system, you can't pass around interface definitions easily:

- https://github.com/sveltejs/svelte/issues/3480 (no dynamic slots)

- https://github.com/sveltejs/svelte/issues/5381 (can't wrap children)

You can always find workarounds for these cases, often using `<svelte:component>`, but React's Javascript/Typescript-centric design avoids such issues before they even occur. For instance, I can trivially define a tabbed interface by mixing strings, JSX, and components, without imposing any DOM-structure. The component that reads this definition can use it to build a tabbed-view on mobile, and a master-detail-view on desktop. It could even build a table of contents.

In the definition, I can still work mostly with strings, but fall back to JSX in the rare case where I do need some advanced formatting:

  const tabs = [
   { name: "Tab 1", icon: <img ... />, content: MainTab },
   { name: <>Tab with <b>bold<b/> text</>, icon: <MyIconComponent ... />, content: SecondTab },
  ]

Again, I like Svelte, but I'm not yet sure whether the better syntax is worth the reduced expressivity.