There's a very good reason that most testators specifically set aside some amount of financial compensation for the person they name as executor or administrator for their estate. After all, handling an estate is stressful work, bordering on a full-time job.
In addition to obtaining records and paying bills, an executor or administrator must do their best to fulfill all of the expectations set by the deceased party in their last will. That could be a pretty difficult job to perform, especially for someone who already has a job or a family to care for.