Great interaction takes work
There is an age-old saying that everything that can be thought of has already been created in some form or another. The problem that differs from every single scenario is not necessarily the practice that implements the solution but the entire product that shows itself through its main and completed interface. While the importance of lean and efficient code is and always will be there, there is of much greater importance to a product that can market itself. But let's take a step back at what great products entail in their user interfaces.
There are a load of toolkits available to create graphical user interfaces today for the web, desktop and mobile but what most of these toolkits tend to do is supplement a key component in creating a product - showcasing originality. In fact, the greatest part about creating a new product is that you have full control over how your users are going to interact with it - you can choose to make task completion inherently difficult or inexplicably easy. In all of interaction design this is quite possibly the most important - work hardest on it over any other.

The only successful product out of that market will be one that can differ itself in great interaction experience. Of course, creating that will not be easy and should not be taken lightly. Efficient code takes much thought into building algorithms that you can depend on. The same goes for interfaces in that successful products take much more thought, time and emotional presence into designing interfaces that you can depend on.