Some do have club only floors. I think the GH NYC does, as did the HR Chesapeake, and Waikiki, but there's no guaranteed you'll be put in one of those rooms if the hotel is full. I haven't been a few times even though I had club access. I know that I was given a choice of a less desirable view on the club floor or a fabulous view on another and I took the view
However, in the case of Waikiki, the club is no longer on those floors. But the amenities are nicer.
I think most do not have club floors and to me, it's really not a big deal. I would like to be closer to a club if there is one, but it's not a deal breaker, nor something I would even complain about, if I'm not on the same floor.