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

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>
  );
}