We have a suggestions section btw, moved it there
I guess I can look into adding a sort button as it has been requested numerous times before, but I just don't think it's that important of an addition to the game. I myself, and I think most players, prefer to keep their bags organised themselves - potions and cards in one bag, alternative armor and weapons in another, junk to sell in another, etc. etc. so you know exactly where the item(s) you need are located. Clicking on a sort button is going to throw that out the window and you will be searching through all your bags for what you need all the time. If you have your armors and weapons in a particular bag and you picked up some junk armors to sell it's going to mix them all together and you might accidently sell something you didn't mean to.
I dunno, I can see some benefit to having it but not a great one really.