We used to mount our dagger boards in foil shaped cases with the board bearing against the inside of the case. This resulted in the risk of the board jamming in the case and being difficult to raise. Now we use rectangular cases with foil shaped bearings to minimize the friction and make the boards easy to raise and lower. I suspect that many sailors may have been discouraged by their experience with jammed daggerboards and this might help to explain the popularity of fixed keels in many modern day sailing catamarans.
This is an example where increased complexity (the addition of bearings) has effectively solved a problem without any significant downside or potential danger, just a modest additional cost.
In many cases the deployment of complex technology is safe, relatively inexpensive and highly effective in its functioning. The headsail furler is a good example of this. In some cases the problem could have been solved with little or no added expense simply by better design.
In some cases the technology employed to solve the problem is way beyond our scope of understanding and in the worst case scenario could be fatal as has been demonstrated by some notable failures related to the application software systems in aircraft, motor vehicles and shipping.
See the full article here: www.rakucatamarans.com/complexity-in-design