JSX. This was never zero cognitive overhead as compared to plain HTML. Folks have simply had 10 years of practice with their Stockholm Syndrome.

With Svelte, you see a script tag with 99% plain JS, some HTML with some basic control and binding syntax, and a style tag with 100% plain CSS/SCSS.

No createSignal(…) with [foo, setFoo]. No props objects. No onCleanup(…) handlers. No createEffect(…) to track reactivity. No render(…) function just to show some HTML. No string template literals to use the framework. No worrying about when to use createMemo(…) or not. Nothing more than a $ prefix to use a store.

Solid (and React et al) is to Svelte as vanilla DOM is to JQuery.