Comment by IG_Semmelweiss

Lindy's law:

For non-perishable things - i.e technologies, ideas, books, institutions - the expected remaining lifespan is roughly proportional to how long they have already survived

Time acts as a filter: what has already withstood a long stretch of disorder is more robust, so the longer it lasts, the longer it is expected to last.

The old nuclear software running on mainframes have passed the test of time. The new software, has yet to.

Nassim Taleb talks about this at length in his book, Antifragile.