Both platform admins and end users have the access to enforce 2-Factor Authentication for their sub-admins and sub-users accordingly. Exceptions can be applied as well.
For the end-users, you need to go to the Settings menu section, then Manage Users, and activate the 2FA toggle button above the list of users.
The admins can apply the 2FA from the Administration>Settings page, by clicking the appropriate checkbox.

You can enforce or exclude a specific admin/user by clicking the Edit button under the Actions column.