Why does UBOS ask for a domain name when installing a new Site?

/docs/users/faq-howto-troubleshooting/why-domain/

UBOS mostly cares about Apps that are accessible over the web. To access an Apps over the web, your browser needs to know which server to talk to (the web is a big place!) and the common way of doing that is to use domain (DNS) names.

This is why ubos-admin createsite asks for a domain name.