Retrieving name, path and directory information of currently loaded file with \currfile

Question

1. I understand that package currfile provides information on the currently loaded file like name, path, directory, etc. \currfilename and \currfileext deliver as promised, \currfiledir and \currfilepath return blanks. Why?
2. I am told that the expl3 core now provides its own access to current filename and path. Is this as documented in ltfilehook, dated 17 June 2021? Since \CurrentFile and \CurrentFilePath compile with \usepackage{currfile} commented out, I take it my system is up to date. However, keeping with the tradition, both \CurrentFile and \CurrentFilePath return blanks.

Anyone interested in providing some clues?

\documentclass{article}
% RN. 24 June 2021
%=======================
\usepackage{comment}
\usepackage[check-declarations,log-functions]{expl3}
\usepackage{currfile}
%-----------------------
\begin{document}
\ExplSyntaxOn
\verb+\c_sys_jobname_str+ = \c_sys_jobname_str 
\ExplSyntaxOff
\verb+\currfilename+ = \currfilename
\verb+\currfileext+ = \currfileext
\verb+\currfiledir+ = \currfiledir
\verb+\currfilepath+ = \currfilepath
\verb+\CurrentFilePath+ = \CurrentFilePath
\verb+\CurrentFile+ = \CurrentFile
\end{document}