Since MariaDB 10.4, the User Permission portion of the MySQL Database module cannot modify data nor add new users. There is a small change with mysql.user.
All user accounts, passwords, and global privileges are now stored in the mysql.global_priv table. The mysql.user table still exists and has exactly the same set of columns as before, but it’s now a view that references the mysql.global_priv table. Tools that analyze the mysql.user table should continue to workas before.