Less code as everyone else mentioned, single file components (CSS is inside your .svelte files too, and isolated automatically), and a general feeling of on railsness that React for me lacked.

State in Svelte goes in stores. State in react seems to go in one of eighteen different mechanisms, which all begin with a 45 minute video of the author’s opinions about the true nature of reactive programming, when all I want to do is store a string.

So... useState? :)

Of course then I got to thinking about how I'd answer the question "How can I put make that useState value accessible at different points in the component tree?" and the answer was "Make a new context with createContext and wrap the context provider in a component which provides the state and write a hook to easily consume the context within a child component" and, yeah, that's not exactly a frictionless dev experience.

FWIW for simple state management in React I've heard lots of good things about zustand: https://github.com/pmndrs/zustand