What problem does this address?

The navigation editor currently uses a few 'hacks' to disable features of the navigation block that the navigation editor can't support. But also to add its own features.

These are (from least to most hacky) :

• Using a block filter to add additional features (menu name editor)
• Using a block filter to disable block supports features (pretty much all of them)
• Using a block filter to remove variations (horizontal/vertical nav block)
• Using a block filter to remove unsupported blocks from the inserter
• Using a block filter to pass props into the edit function to disable some features. (item justification, submenu indicator, block placeholder)
• Potentially using CSS to hide some parts of the block interface. (Navigation Screen: Update Navigation Block Toolbar to only include list view and menu name #28856 (comment))
• Using CSS to completely re-style the block (accordion style submenus)

So this is a good opportunity to catalogue those and discuss if there's a way to improve a situation which will probably only become more difficult as the nav block receives more features.

What is your proposed solution?

Potentially more of these options could be moved to block supports.

Some of them might also be toggled by a theme.json setting, which the nav editor could more gracefully override.