As someone who moved from vbox to QEMU (and is happy about it)...
Virtualbox is one product, one package. That’s easy to sell, install, understand and google when you need help.
Virt-manager, libvirt, QEMU and kvm... Takes more time to understand, and googling it when you need help requires you to partially understand it. Kinda chicken and the egg.
Also with Vbox I get the VMs desktop scaling to my Vbox-window, as opposed to the other way around, which I get with QEMU. That still annoys me slightly.
Virtualbox is one product, one package. That’s easy to sell, install, understand and google when you need help.
Virt-manager, libvirt, QEMU and kvm... Takes more time to understand, and googling it when you need help requires you to partially understand it. Kinda chicken and the egg.
Also with Vbox I get the VMs desktop scaling to my Vbox-window, as opposed to the other way around, which I get with QEMU. That still annoys me slightly.