It is not easy to debug access denied in Drupal (especially in views), This is why I have added a lot of "reasons" when using
Unfortunately, when an access Denied arise, I couldn't find any log or anything else in which the Reason was properly outputted to give me a clue on why this acces was Denied.
Note: As pointed out by @Clive, if the access is calculated to display a page/route, it will be displayed in the 403 response. My question is not about this kind of access, my question is about (for example) entity access (ex: view or edit a user)
Am I missing something?