The website most independent properties have is either five years old or expensive to change, and in both cases what it advertises is a screenshot of inventory rather than inventory.
A site built on the property's own data shows live rooms, live rates and live availability, because it reads the same catalogue the desk sells from. Nothing to re-upload when a rate changes.
Templates are schema-driven: the blocks and collections a template accepts are declared, so editing content cannot break the layout and upgrading a template does not discard the content.
A custom domain points at the property's site directly, so the booking journey never leaves their brand.