For years we had an IKEA Hemnes daybed.
https://www.ikea.com/gb/en/products/...-spr-59186124/
When you open it up it becomes a king sized bed.
I did replace it with two very wide "chairs" that have a twin bed hidden in it. I found the daybed not as functional for everyday use and sitting on it but it was nicer to sleep on then the fold out twin beds. Since we use the bed more for sitting on then sleeping, it made sense for us.