I've worked with software that has to work. Our customers put it in a lab where they beat on it in simulation for 3 more, months - any bugs and they stuck with the old version. (which is one reason land lines were so reliable in the 1990s) We did a code freeze 6 months before release in hopes of catching everything.

Most software nobody cares if it works or even is possible for untrained humans to use, and it shows.