We are working on more important interfaces currently. But this issue is on our list. Any interface that goes into your minigame area of your interface has not been touched.
I have currently been focusing on child windows like dungeoning party interface.
In regards of clutter. There are lots of interfaces in RS3 and we have to make a choice on what is important on mobile. For example we don't have room to have all your action-bars open at once. Well we do but your wont be able to see the game or tap on anything :)
My recant improvements like the new NPC chat and stat globes help with the overall usability and appearance of mobile.