What problem does this address?

The navigation block does a great job letting you add nav menus anywhere on the site. However, it's extremely opinionated in how those menus will appear and function (submenus are always hidden and set to absolute positioning, for example).

Menus can appear in a multitude of ways across sites, from main menus at the top of the site (which often function the way this block does), to flyout menus with accordion-style submenus, to mega menus, to side menus for site sections, to a thousand other types that I'm not mentioning.

What is your proposed solution?

It's not realistic to expect this block to offer every type of menu format, but it would be really nice to have an option to turn off all styling and functionality and just output a simple unordered list like wp_nav_menu does so that the theme can apply its own styling and functionality when needed. This would allow for the excellent menu building features included in this block to be usable for many types of menus.