You can run multiple OSes simultaneously on Linux itself - Linux can run VMs just fine. I.e. Linux guests on Linux host and so on. Take a look for example at virt-manager (libvirt / qemu + kvm).

And WSL is a limited VM using HyperV anyway. If you want to run a VM, you can as a well run a proper one which isn't limited and runs a full blown distro with sane configuration.

So WSL is definitely not more powerful than normal Linux.