Templates are not static images. They store the underlying HTML structure of both sides plus the field definitions, so editing a field reflows the layout instead of breaking it. If a name is too long for the original layout, the template adapts; the design does not silently clip.
You can also regenerate the back of a template independently — useful when the front identity is settled but the back is still being argued about. The variant comparison view makes it easy to lock the winner without losing access to the rejects.
Templates also help with the awkward middle ground where a company has a brand but no formal brand kit. The template captures the choices implicit in the website — heading hierarchy, the proportion of weight to whitespace, the way colors are paired, the voice of the headline copy — and freezes them as a print artifact. Months later, when someone asks what the secondary brand color is or how the logo should sit next to a person's name, the template is one of the places it can be looked up. That makes it a small but useful reference point for teams that have outgrown a single founder's taste but have not yet hired a designer.