The software field exploded in the past half a century, producing a huge volume of activity producing a huge amount of cruft. A lot of the unreliable stuff gets shaken out; so what we see is a biased sample consisting of the successes that remain. Software that is halfway successful gets to be maintained, and over many years or decades, the reliability improves.
Two words: survivorship bias!
The software field exploded in the past half a century, producing a huge volume of activity producing a huge amount of cruft. A lot of the unreliable stuff gets shaken out; so what we see is a biased sample consisting of the successes that remain. Software that is halfway successful gets to be maintained, and over many years or decades, the reliability improves.