The information is hidden inside the chosen person, or Secret-Keeper, and is henceforth impossible to find."
However, the Potters actually made Peter their Secret-Keeper at the last minute in an attempt to misdirect Voldemort.
The Order of the Phoenix also uses the Fidelius Charm to conceal various safe houses in the later books.
Thus, it would have been an effective way to hide the Horcruxes, but Voldemort never used it.
But Voldemort doesn’t want to depend on anyone, controlling his followers through fear more than anything else.
Voldemort sometimes misses even the most logical strategies in his quest to be something other than a mere man.
