I would suggest working on the material of the leather more(i think its leather?)
To me, it doesn't quite look like leather yet.
I also noticed that you don't have wrinkles, read some comments about you not wanting to sculpt and instead keep this low poly.
But instead of sculpting, use textures for wrinkles, tiny wrinkles are all over leather, new or used.
Another thing, i noticed straight away the there are no welds on the chairs frame, without that this would be a chair molded as one piece, which is unlikely and expensive. So i suggest adding that, you can do that and keep it low poly, welds are usually not visible right away on chairs, but when theyre not there you notice it ^^
That would be what i have to say
Other than that its a nice set! I wouldn't mind having a set of my own