Without metal brackets to hold the mattress on the bed, the mattress can slide off the bed, with the person still on it, on the floor, and possibly unable to get up.
Twice, the pumps which raise the bed, or lower it, and which keep the mattress even on both sides, have needed to be replaced. If one side is not replaced, leaving just one pump working, the mattress slants, & the person can find the unevenness tilts them to one side of the bed, causing additional pain, and difficulty sleeping.