Weirdly, UI interfaces are also a problem in the game world. Where we want to have a designer or artist design and implement something in a game in a fast way we often resort to using Scaleform[1]. It is flash based tool for games, within the industry it is notorious for how slow and inefficient it is. A simple UI element can often be more costly than a major in-game 3D object.
We are willing to pay this extra cost for these elements because they are often required to be quickly put together and then iterated on over a long period of time in a very dynamic and changing system. Some elements may be moved from Scaleform into a more native implementation but for the most part it is left to be slowly parsed and inefficiently rendered.
Basically, where we need fast changing interfaces that arent necessarily implemented by high skill programmers then we are going to take a performance hit to get the same level of visuals we could get if we had the time and manpower to approach it better.
We are willing to pay this extra cost for these elements because they are often required to be quickly put together and then iterated on over a long period of time in a very dynamic and changing system. Some elements may be moved from Scaleform into a more native implementation but for the most part it is left to be slowly parsed and inefficiently rendered.
Basically, where we need fast changing interfaces that arent necessarily implemented by high skill programmers then we are going to take a performance hit to get the same level of visuals we could get if we had the time and manpower to approach it better.
[1]http://gameware.autodesk.com/scaleform