React optimization: what is the goal of applying useMemo to useState return values?

Question

In this article on state management with context API, the author applies useMemo to useState return values this way:

function CountProvider(props) {
  const [count, setCount] = React.useState(0)
  const value = React.useMemo(() => [count, setCount], [count])
  return <CountContext.Provider value={value} {...props} />
}

I am not sure to understand the goal of this optimization:

• 1/ is it to prevent re-rendering in case any of the props change,
• 2/ or can setCount itself change spuriously?

If it is for 1/, isn't it equivalent to the following code? (because: what props other than children would we want to pass to the context provider? and if children change, a re-render is desirable)

function CountProvider({children}) {
  const [count, setCount] = React.useState(0)
  return (
    <CountContext.Provider value={[count, setCount]}>
      {children}
    </CountContext.Provider>
  );
}