Because they are for different use cases. I use QEMU+KVM on desktop for games and 3D CAD software, because of its undeniable performance advantage. But on work laptop, I use VirtualBox to test my software on different platforms. On VirtualBox it’s relatively easy to initialize a VM, configure network, file sharing and device passthrough, and its snapshot feature allows me recreate the same environment for troubleshooting
Wait till bro find out the program written in the “memory safe language” depends on many libraries written in C