Why when I use the getData() it shows it as empty, but works when I fetch without it?

// "use client";

export default async function Home() {
  async function getData() {
    const res = await fetch("https://jsonplaceholder.typicode.com/posts");
    return await res.json();
  }

  const res = await fetch("https://jsonplaceholder.typicode.com/posts");
  const data = await res.json();

  return (
    <>
      Why this shows an empty data {} : {JSON.stringify(getData(), null, 2)}
      And this not: {JSON.stringify(data, null, 2)}
    </>
  );
}

Using NextJS with app folders