But that is how most of the companies work (and did, for centuries). Very few roles affect critical flight safety, nuclear control or other things that need a bunch of nines for reliability, written and fire-drilled fallbacks, etc.

For everything else the general mode is "can we make it work well enough". And when it breaks, well, we will curse and pry it open and either fix or rebuild it. There are many stories of a particular thing that was built long time ago by folks who are long gone and no one knows how it works or even where it physically is.

And it works fine; usually better than ensuring complete reliability from the get-go, when it is not clear if it is a long-term core feature or a kludge that will be obsolete soon. My 2c.