It's not far from it. Software development is in small company with respect to the need for constant re-education and skill maintenance. The vast majority of developers with skills from just 10 years ago are wholly unemployable right now.
Replacing these systems is extremely difficult since they're so relied on a replacement needs to be nearly flawless form the start. If you stumble upon on a bug in your international wire transfer code you could be messing up a $10 billion international aid wire that was meant for hundreds of factories.