I use hides now, but will be transitioning out of them. I use them because the rack is open on all sides since I used melamine shelves and two by fours. But I'm thinking I'm may close the sides off and then it's up against the wall, it'll create a natural hide.
I have hides. It helped with the small ones who each had two. As they get bigger it gets cut down to 1 big hide.
For the two big girls I have, I sometimes put it in, sometimes take it out. When it's in, they know how to push it forward just enough so they can fit behind it, and it kind of lets them create their own perfectly sized space in the back.
Mine all have and use hides. Once they are bigger, it's just one big hide. However, I took my bees out because she has been breeding, and I also think it will be too crowded when she lays.
If nothing ever changed, there would be no butterflies.