Ben and Jerry have a pigloo each, a soft tunnel, a cuddle cup, two large cardboard tubes, a rainbow stick bridge and a plastic step stool plus the inevitable mountain of hay and the odd cardboard box. They don't have all these available at the same time as I like to change them around at cleaning time and offer them a change. Although they do like to hide they also like to sleep where they flop and if that's in the middle of the open so be it. I think as prey animals they need somewhere to hide if they choose to. When they feel confident they may sleep in the open as mine do. They are in my living room with the usual living room noises of the tv and people coming and going they don't seem in the least bothered. The only time they look up and wheek is when someone crinkles a crisp packet or they hear the fridge door followed by chopping sounds. If I call their names from my chair they may grace me with a look of acknowledgment or they may not, cheeky things. They always come to see what I've got if I call ''breakfast'' no matter what time of day!
If you offer them cover they will use it and as they feel more confident they will choose when they want to hide and when they don't. I think it should be available. It doesn't mean they will hide all the time, they need handling and interaction and over time they will grow in confidence and will be out of it more than in. At least this has been my experience.