Seeing systems used in the most advanced areas of human civilization never fails to amaze me. They have been created half a century ago yet still functioning flawlessly in the autonomous, harsh environment of space. Meanwhile, I consider it a win if my Python API server survives a month without breaking. I'm always wondering, how did those engineers create something so robust, while I, despite standing on the shoulder of decades of software engineering progress, seem unable to avoid introducing bugs with every commit?
Management then cared that their one chance would work. Today management just wants it to mostly work.
Incentives and goals are very different between the two. We could very much build even more incredible things today; and would argue that we actually do. Just only in the places that seem to matter enough to do that type of special effort for.