When you design forms with multiple related fields, using the fieldset element helps you group these fields together in a way that is clear for everyone. The legend element provides a descriptive heading for the group, making it easier for users to understand the form's structure. This approach is especially important for accessibility: screen readers will announce the group and its legend, giving users important context about the information being requested.

By grouping related fields, you make forms easier to scan for sighted users, who can quickly identify logical sections. For users of assistive technologies, the grouping and legend are announced, improving navigation and comprehension throughout the form.