Lock in is huge. Lots of places like utilities and government departments wrote stuff on mainframes in the 1970s and 1980s that could not have been done on any

Lock in is huge. Lots of places like utilities and government departments wrote stuff on mainframes in the 1970s and 1980s that could not have been done on anything else. Then they used some non-standard databases or other software for which support has gone and shifting is very hard. Now even though 'mid-range' machines have been able to do the work the mainframe does and have been able to do so for more than 20 years many 'enterprise places' are still tied to a mainframe. These places often have failed attempts that costs ten of millions or more to get off old mainframe software as experience. Corporate places often hate their IT department (it's a cost centre that fails on projects) and IT doesn't like the rest of the department much (they don't respect IT for keeping things going) and it all winds up in a toxic situation. In the meantime IBM continues to make huge, huge margins on mainframe support.....