I'd recommend reading up on it, and perhaps trying it, because it's very useful.
For folks lamenting that the (awesome) Asahi efforts are challenged by reverse engineering of changes from M2 to M3, and so on, those changes vanish into the abstraction, but their benefits do not. That's why i switched from Asahi a couple years ago to UTM in apple silicon hypervisor mode.
https://developer.apple.com/documentation/hypervisor https://apps.apple.com/us/app/utm-virtual-machines
The point is some people who want to run Linux mostly do not want MacOS. You suggest to "just run MacOS" (the thing they want to avoid) and virtualize Linux. That defeats the entire purpose, then you could just as well skip the VM and run Mac apps. Yes, there are a few specialized applications people might need Linux for but that's mostly not why they install an entirely different OS. For the occasional obscure programm that doesn't exist in the Apple ecosystem VMs are a good option, absolutely. Everything you do in the VM still runs on Mac though and you depend on Apple for security, privacy and trust in general.