Libvirt is a handy way to manage containers and virtual machines on various systems. On most distributions, you can only access the libvirt daemon via the root user by default. I’d rather use a regular non-root user to access libvirt and limit that access via groups.
There are some situations where you want to do the opposite of creating a wireless hotspot and you want to share a wireless connection to an ethernet connection. For example, if you’re at a hotel that offers only WiFi internet access, you could share that connection to an ethernet switch and plug in more devices. Also, you could get online with your wireless connection and create a small NAT network to test a network device without mangling your home network.