A re-render in React is not as heavy as you'd think it is. It's painting the DOM that takes resources, and people conflate the two. But if your whole component re-renders because of a change in context, yet nothing on the page changed, you will likely not notice the render even on low-end devices.

I still think Zustand is the simplest state management, while staying efficient. It's similar to the old Svelte stores. But I have used many state management tools and the re-renders were not the problem when it came to speed.

not if the compiler stops the unneeded re-renders.

A "compiler" to solve the issues the library created, awesome. It doesn't solve many re-renders tho, as React re-render full components, not only the HTML/Text Nodes that changed.