Standard objects can’t be on the detail side of a custom object in a master-detail relationship. There are OOTB Master Detail relationship between Standard object, e.g. Opportunity and Opportunity Product (Opportunity Line Item), but, a new Master-Detail relationship cannot be created between standard objects or between standard object and custom object given tha Standard object is required to be at detail side.
Please find the below screenshot where there is no option to create a Master-Detail Relationship on standard object.
Security/sharing of detail/child object in a Master-Detail relationship is controlled by master/parent, that might be one of the reason why standard object have restrictions.