Depending on where is the author decides to go, it has a LOT of potential.
Like this "death god" (for lack of a better word) could throw him into the lives of only successful people that all get unlucky one way or another to proves him success can just sometimes hang on a thread.
Or he could send him into a wild variety of characters (I dunno, a soldier, an artist, a poor guy that got isekaied by a slasher...) because death can be terribly unexpected.
And at the end I kind of expect a twist like "now you get back into your original body and keep trying again".
Or maybe I'm totally wrong and it will go in a very different direction.