One thing that the IT world (being a field which is only a few decades old) is going to have to come to grips with is the fact that, in general, infrastructure

One thing that the IT world (being a field which is only a few decades old) is going to have to come to grips with is the fact that, in general, infrastructure doesn't necessarily get thrown out just because it has grown a bit long in the tooth. In the US we have physical infrastructure which is many decades to centuries old, and elsewhere in the world there's still infrastructure in active use which dates back to at least Roman times. Now that old stuff certainly may not be ideal by modern standards, of course, but to the extent that it gets replaced this is usually done relatively slowly, and some of it may yet end up sticking around indefinitely.