You get into any big organization and legacy becomes a larger and larger part of the way things are kept running. Hell just for shits and giggles look at the back end of blood banks, government, airports and non blood banks back end infrastructure. I would be shocked if anything was running on less then a decade old software.

Maybe on the backend or specialized single purpose appliances. Running decade old OS’s on workstations is negligence boardering on malpractice.