I skimmed the docs for multiple hypervisors (qemu, vmware, virtual box, hyper-v), it looks like only Qemu can directly boot the raw image, but everything else can convert the raw image to a native format and then boot it. It does take an extra, often command line only step to get it booting though which is less than ideal.
This is a feature of QEMU and not the raw image itself. Most hypervisors have a preferred image format. The two most popular ones for QEMU are qcow2 and raw.
Others such as vdi and vhdx can be easily created with the qemu-img tool, which allows easy conversion between image formats. I've successfully run the same raw image in QEMU, VirtualBox, HyperV, and VmWare just by converting it and booting it.
Assuming you even have access to the storage repository where your disk images reside. Which you don't immediately do in many cases.
Yes, for sure it can be done. But unless you have a habit of doing it it is likely going to be much quicker to boot from a live ISO and do it from there. And by then it all seems rather ridiculous.
