Provide menu item integration for views

Abstract:

Drupal views should provide flexible functionality for listing different types of entities data and connecting all their relations. The menu system currently seems to be hardly separated from this functionality ("something very different" ;)).
This seems strange and leads to flexibility problems when solving (quite common) tasks like listing up all child nodes of the current node (node hierarchy). This is for example typically the case on overview pages in the menu tree (which shell show the same children hierarchy as the menu itself).

So I'd suggest to add better menu relations for Drupal 8 views like modules like https://www.drupal.org/project/menu_node and https://www.drupal.org/project/menu_node_views did before using workarounds.
The reason why I see this in core is, that both components (and especially the menu) is part of core and from my point of view this is a missing connection / functionality between menu and views.

Problem:

There is no proper D8 views integration for menu and node (or perhaps even other entities) to use these relations in views.

Context:

Building views which show the subpages of the currents node menu entry for example is only possible writing special custom code or module. Views is not really helpful here and if it is, then it's not user friendly.

Proposed solution:

Extend the menu_link_content (and perhaps node) modules for a better menu_link views relationship integration to provide (contextual) filters for menu_link item parents, menu item id's, menu item referenced nodes, etc.

The views integrations should provide similar functionality of what Taxonomy Terms already provide, as much as possible, for example

• Parent / Child & Depth handling (also allow relating items assigned to children menu items)
• Expose all menu item properties e.g. allow to sort by weight
• ...

References:

Drupal 7 solutions / "workarounds" (if I may call it so because of the additional tables tracking the relationships).
https://www.drupal.org/project/menu_node
https://www.drupal.org/project/menu_node_views

Drupal 8+:
https://www.drupal.org/project/menu_entity_index
https://www.drupal.org/project/views_menu_children_filter

Thank you all very very much for your great D8 work!

It would be really really nice to discuss an integration like this. I think Drupal is lacking this since D6.