IMO, VB allows the running of another OS so you can prevent your host OS from being fingerprinted. Windows SB (like SandBoxie, Shadow Defender, Shade etc) cannot do this.
Pros and Cons of Windows Sandbox vs VM here
Windows Sandbox vs Virtual Machine
www.gigxp.com
FI, you can run WIndows SB in VB provided you have a AMD machine
You can enable Windows Sandbox if you have installed Windows 11/10 in VirtualBox. You need AMD CPU to enable Windows Sandbox in VirtualBox.
www.thewindowsclub.com