Currently none of the API endpoints have the ability to list all users which count as licensed users for each of Atlassian products.

• /rest/api/3/users/search - we can't exclude Confluence users,
• /rest/api/3/user/permission/search - this endpoint would be perfect with the "ASSIGNABLE_USER" permission filter, but it works only for "up to the thousandth user"; there is a fallback to use /rest/api/3/users/search, but there is no information about groups/roles/permissions
• /rest/api/3/user/assignable/multiProjectSearch - similarly to the endpoint above, works only for "up to the thousandth user",
• /rest/api/3/applicationrole - a problem exists when a user has access to multiple products, so one cannot get a proper count of accounts.

This API should be accessible through any of the development frameworks (Connect, Forge, etc.)