This video might be helpful. Leptos uses Signals, borrowing ideas from SolidJS to update the DOM. There's no VirtualDOM like React. Svelte also doesn't use a VDOM.
When there's a state change React has to rerender the entire VDOM tree and the diff it with the real DOM, whereas using the Signals model those frameworks make the change directly in the real DOM.
I'm not sure how Svelte manipulates the DOM exactly but I it's similar to how it's done with Frameworks that use Signals such as Leptos and SolidJS.
I would say Developer velocity is key if you're a developer. Svelte is a big winner here as it's mental model is easier to understand than React's.
This video might be helpful. Leptos uses Signals, borrowing ideas from SolidJS to update the DOM. There's no VirtualDOM like React. Svelte also doesn't use a VDOM.
When there's a state change React has to rerender the entire VDOM tree and the diff it with the real DOM, whereas using the Signals model those frameworks make the change directly in the real DOM.
I'm not sure how Svelte manipulates the DOM exactly but I it's similar to how it's done with Frameworks that use Signals such as Leptos and SolidJS.
I would say Developer velocity is key if you're a developer. Svelte is a big winner here as it's mental model is easier to understand than React's.