You got it completely wrong. WSL1 was a system call translation layer, and everything worked directly on the Windows kernel, like Windows programs do under WINE. WSL2 is an standard Hyper-V virtual machine, no more no less, with a custom Linux kernel build and a ext4 root filesystem stored in a .vhdx image. Every process runs as a native Linux process under the Microsoft's Linux kernel, _inside_ the VM. What makes it more convenient than simply opening the Hyper-V manager and creating a VM is ease of installation, maintenance and integration with Windows (using the 9p protocol to allow file access).