Is it reasonable that the sofa is not against the wall, and is there a better design

If you don't pay attention to Feng Shui, that's okay and there is no problem. However, if you look at it according to feng shui, there should be a backing behind the sofa: the so-called backing, that is, backing the mountain, means that there is a solid wall behind the sofa and is reliable, and there are no worries, so as to conform to the way of feng shui.

If there are windows, doors or passages behind the sofa, and there is no solid wall to reliably do it, it means that there is no backing behind it, and it is empty, which is not conducive to the development of the career. If the back of the sofa is indeed not as reliable as the solid wall, the workaround is to place a low cabinet or screen behind the sofa, called an "artificial backer", which can also play a remedial role.

There's nothing left without leaning against the wall!

It won't affect anything. >>>More

It can be, but it feels awkward, if the decoration and furnishings of your home are really not allowed, it is recommended that you put a large cabinet between the wall and the sofa.

Upstairs, this depends on the humidity of your living room, of course, you should also pay attention to this, it is best not to lean against the wall.