"While its predecessor, effectively a translation layer, was the technological tour de force, WSL2 did the previously unthinkable and dropped a Linux kernel into Windows."
No they didn't, they dropped the Linux kernel into hyperv... They basically made it a full VM because subsystems are hard. Sure, they've integrated it a bit to make it seem part of windows, but it's just a VM. Because it's hyperv based, that also stops you using their competitors virtualisation software like virtual box or VMware. It's very clever from a marketing point of view.
Fyi I had seemingly integrated desktop applications from Windows running on a Mac on 2008 thanks to VMWare Fusion using unity mode.