For buildings not collapsing, the main thing that matters is that the structure's strength is larger that the applied forces. Edge cases can be solved by adding more material, or more intelligently by having enough redundancy that you have enough strength even if a small number of components fail.

This, of course, does not apply to software functionality - you can't fix bugs by "more CPU power". However, if you look in the places where you can apply this methodology - like cloud services - you find that they are indeed very reliable.