impdp in Oracle. Why it does not create users?
The documentation states, that impdp will create uses, when the dump file contains the create user statements:
If the schema you are remapping to does not already exist, the import operation creates it, provided the dump file set contains the necessary CREATE USER metadata and you are importing with enough privileges.
So either your dump file is incomplete (for example due to missing privileges) or you are lacking privileges on the target database.
So please check your privileges on both, the source database and the target database. Please update your question with then according information. For the export to include the schema definitions, you must have the DATAPUMP_EXP_FULL_DATABASE privilege.