They may imagine no daily life a lot better than the existing, and so they wanted To make certain it would keep on after Demise. The ba, or "soul", was free to fly out on the tomb and return to it. And it was the akh, Probably translated as "spirit", https://ducttapechallenge12344.losblogos.com/34254275/the-smart-trick-of-randy-mummify-that-nobody-is-discussing