These new fangled VMs
Heh Heh I never did trust thwn new fangled VM machines when I was running them on the old IBM 360 type machines in the 1980s. Sure it is wonderful to have new shiny toys in your play room, provided you can convince the business owners to provide the funds to convert the old systems that are running "just fine" at the moment.
Emulation of hardware/software doesn't always provide a solution. I had to deal with a situation 15 years ago where a section of code written in Wang COBOL was resolutely single threading on IBM mainframes and refusing to run faster regardless of the size/number of processors thrown at the task. It was an absolute bottleneck in terms of transaction processing throughput. Original documentation of the business logic encoded in the section of code had long been lost in multiple company mergers and "rationalisations.
The problem is only going to get worse as program developers move further away from the hardware code protected by increasingly complex layers of middleware software.