CRUD for all contents in drupal

there are contents in drupal that once added, cannot be deleted
eg: menus

others have delete but have traces in the database even the cron was initiated.
eg: modules, content, content types, block etc..

if this is working as designed,
i propose that theres an option that will skip those permissions that make them fully crud in the user interface and dont need database knowledge to crud things.

why do we need to have database knowledge when everything can be done in the web based interface.