Complications are mechanical watches that are incredibly difficult to design and build. The reason being: they're asking for it! They try to solve many–and difficult–problems at the same time. Complications are seen as a challenge for pure prestige, a celebration of craftsmanship and virtuosity. The more complicated the solution, the more admirable.
These features, once invented by scientists for good reasons, have kept beautiful names: Display of leap year, Equation of time, Display of Easter date, Display of true local solar time, Moon phases, Tourbillon... We surely need that every day!
While we, poor UI and software engineers, struggle to design systems for simplicity and ease of development, these fellows somehow have the opposite objective. In their industry, a remarkable design will comprise as many individual parts as possible, in order to implement as many useless functions as can be imagined.
How fair is that? :-)