Traditional Tatami and Futon:

Tatami and Futon Bed:

Futons are great.
We got a queen size futon that fit on a folding sofa-style frame for our guest room in about 2004. Eventually it became our son’s bed, when he was in middle school. It is far and away the most comfortable mattress in the house. We just happened to live near a futon store when I bought our futon, so I tried each grade/thickness before buying. I bought the second most expensive one because it felt better than the cheaper models and tied with the highest priced one.
It’s basically a big, well-packed pile of cotton on a wooden platform. There is nothing that can break. I wish we had this for the master bedroom.