It might be used for special applications, but not for your typical server that is connected to the internet, simply because it's horribly slow compared to the virtualization support (VT-x / AMD-V) most modern CPUs offer since at least 2010.
Right, if you're running on x86 hardware.
The use case is probably non-x86 hardware running x86 VMs.
For example, I remember using qemu to emulate RPi with ARM software emulation on my x86 machine.