Not even just modern hypervisors. The IBM mainframe hypervisor z/VM (and its predecessor VM/CMS) has supported nested virtualisation for decades. It was an important tool to support its own development (especially considering that mainframes were expensive and not even IBM could afford to give every mainframe OS developer a whole mainframe to themselves.)

Because, of course, its not a emulator

I use nested virtualization for Windows Desktop -> Linux VM -> minikube. Works great.

Obviously you could just run minikube under Windows, but then from the Linux VM you can't "minikube ssh" and whatnot, so nested virtualization makes everything a lot simpler.

You can even do nested virtualization without hardware support, it's just super duper slow and not a lot of hypervisors think it's worth the complexity increase.

Neither WINE nor WSLv1 use virtualisation. WSLv2 does use virtualisation however; but WINE still isn't a VM.