What is the purpose for adrenal glands other than to release stress hormones?

Lovely adrenals: You're referring only to the interior part of the adrenal glands (medulla) -- with norepinephrine and epinephrine. The adrenal gland also has a cortex that secretes steroid hormones, without which you'd die. Aldosterone helps control your electrolyte balance and blood pressure, so that you can stand up without fainting. The adrenal cortex makes glucocorticoids & sex steroids from cholesterol.