There are a lot of practical reasons to set up an OS like Windows 10 in a VM rather than using it as a native installation. If you have to deal with files you can't trust, need to test multiple OS ...

So, you missed Microsoft’s Oct. 14 deadline to upgrade before the end of Windows 10. Perhaps your PC does not have the 4GB of RAM or TPM 2.0 needed to run Windows 11. Now you can upgrade anyway. But ...