Caporegime
At one point in time, humans slept on hard floors in caves or on some sort of Hay. A bad mattress will destroy your back, and sleep, ask me how I know!
Do what ever is best for your sleep habits.
At one point in time humans also ran away from dinosaurs, hit things with clubs, wondered where the big yellow thing in the sky went at night, and died before they were 20.
In summary, they weren't that smart so I wouldn't take bedding advice from them