I fail to see why I would want multiboot. If I do need to run software from two or more different OSes on the same hardware then it's strictly preferable to run

I fail to see why I would want multiboot. If I do need to run software from two or more different OSes on the same hardware then it's strictly preferable to run them at the same time and/or switch between them without losing any context/state of the software in the other OS. I can do that decently with virtualization. Having to reboot is a really, really big drawback that's justified only if it's otherwise impossible or impractical to achieve what you need - but it is possible and practical, so multiboot is not really necessary.