The problem with legacy hardware
is generally that the software service it provides is either beyond the capacity of current programmers to reproduce, or too expensive to warrant the effort to reproduce. (My previous employer running a risk management tool written in Cobol, ported multiple times and ended up running on a huge HP-UX system).
There used to be a market for migration tools in the late 90s / early noughties for certain types of OS or Application, but they were riddled with problems and generally crap. Now, budgets have dried up and enthusiasm for the risk of change has dropped.
(I am currently right now at work, migrating an application from an older Linux box which is exposed to Heartbleed, to a newer Linux version that has a patch out. It took news headlines to get the customer to pull finger and pay the money to move. And there is a good chance the interfaces that break upon this move, the customer will have no idea how to fix)