@foone Not just software, this applies to pretty well everything else that groups of people do.

The answer to "why don't we just do X" is usually one of

(1) a good answer
(2) something that was a good answer at the time, but the world has changed since then and that problem has gone away
(3) nobody knows.

So, if it's (1) there's no need to change anything.

It's because (2) pretty well always happens eventually that how we do things is (or at least should be) reviewed from time to time.

And it's to avoid (3) that it's a good idea to ensure you've always got a corporate memory. Which means, for example, not sacking all the old people.