UTL_FILE directory name changes oracle 19c
Starting with 18c, the UTL_FILE_DIR parameter no longer exists, thus the usage of directory paths instead of directory objects in UTL_FILE is no longer possible.
Desupport of UTL_FILE_DIR Initialization Parameter

Starting in Oracle Database 18c, the UTL_FILE_DIR parameter is no
longer supported. Instead, specify the name of a directory object.

Even in earlier releases, the parameter and usage of paths existed only for backward compatibility.