I'm a big proponent of "simple".
I try to keep all my software as simple as possible. Software architecture, UX and in features. But I often fail at that.
Simple is hard. It's probably the hardest of all software things. "Just pull in a library", "just add a layer of abstraction", "just make it configurable", "I'll think about that later", are just a few of the pitfalls.
Simple is hard. But, I believe, also the most important feature of software.