I'd say something like TeX might be a software cathedral, and even that one isn't going to last much longer than Knuth himself (almost everyone today doesn't run TeX, they run a compatible software platform, some are even entirely different).

But even a Cathedral changes over time, and your work may not last; but all human work is a shrill scream against the eternal void - all will be lost in time, like tears in rain. The best we can do is do the best with what we have in front of us. And maybe all the work you did to make sure your one-off database code correctly handled the Y38 problem back in 2000 will never be noticed; because your software is still running and didn't fail.