You seem to be confused about what a Horcrux is and its use.
A Horcrux is used to make sure your soul stays on earth when your body is destroyed. It is created with a murder as it will shatter your soul and allow you to put a part of it inside an object.
Then, when you die, your body is destroyed and your "main" soul is let to wander:
* If you don't have any Horcrux it will continue its journey to the unknown.
* If you have a horcrux (or more), however, it's a bit of your soul that will stay on earth no matter what, linked to the object in which you put it. So, if the body which contain your "main" soul is destroyed, instead of going, your soul will wander around until you find a body of your own. The bit of souls concealed in your horcruxes will remain untouched as their only use are to make sure your soul won't make the journey.
As for the other use of a Horcrux, in Harry Potter and the Half Blood Prince, <PERSON> says something interesting:
"...I think I know what the sixth Horcrux is. I wonder what you will say when I confess that I have been curious for a while about the behavior of the snake, <PERSON>?”
“The snake?" said <PERSON>, startled. “You can use animals as Horcruxes?”
“Well, it is inadvisable to do so,” said <PERSON>, “because to confide a part of your soul to something that can think and move for itself is obviously a very risky business. 773
However, if my calculations are correct, <PERSON> was still at least one Horcrux short of his goal of six when he entered your parents’ house with the intention of killing you.”
That's because usually you'll want to put your Horcrux in someplace safe where nobody will ever look. Breaking your soul to pieces is indeed a very dark thing to do and you don't want part of your soul to go wandering around. We can see in <PERSON>'s mind of King <PERSON> what someone whose soul is too shattered would become in the form of the hideous infant and understand why it is such a big deal and an important thing. (It's your soul!)
For example, the diary was a fantasy of <PERSON> who wanted to reoppen the Chamber of Secret (and thus was proven to be its unsafest Horcrux).
You don't want your Horcrux to remake your body of its own as it would put it in an unsafe situation, but instead would have to entrust someone to help you rebuild your body (<PERSON> in the book) or make something else ready for your resurrection by the time you die (No clue about what that would be though). And the Dark Lord didn't have that something in place by that time, as his plan to make himself immortal obviously wasn't finished: he didn't had all its Horcruxes, as he wanted <PERSON> to be the murder that would allow him to make his sixth and last <PERSON>.
Plus, <PERSON> was really surprised when none of his Deatheaters came to him to help him after his death as he bragged many times he conquered death. His most faithful deatheaters (<PERSON>, <PERSON> Jr) being imprisonned at Azkaban. 773