The people who designed their systems such that they could be easily transitioned off of IBM have done so long ago. Those systems now run exponentially cheaper and have access to more resources.
Vendor lock-in was just as much of a problem then as now.
Yes because people in the 80s writing COBOL were writing AbstractFactorySingletonBeans to create a facade to make their transitions to newer platforms easier....
Well, our next iSeries is a whole lot cheaper than our current iSeries and quite a bit more powerful. The Power 9 is not something I would call a dinosaur.
IBM's prices haven't changed at all since the 80s. They're still four times as expensive as they should be.
Sounds like you've described IBM being priced exactly right, given their tenacious longevity.