Hello,
Emacs has a built-in function 'find-file-at-point' (or 'ffap'), which works great with the standard latex-mode. For example, putting cursor on the argument of the command
\input{~/Downloads/myfile.tex}
and calling 'M-x find-file-at-point' causes visiting the file under the cursor. It works similarly with the \usepackage command.
The AUCTeX package comes with LaTeX-mode which does not support this functionality. But it seems that the older versions of AUCTeX did.
As a workaround I put these lines in my .emacs
(eval-after-load "ffap"
'(progn
(add-to-list 'ffap-alist '(LaTeX-mode . ffap-latex-mode)) ; same as for latex-mode
(add-to-list 'ffap-string-at-point-mode-alist '(LaTeX-mode "--:\\\\$+<>@-Z_[:alpha:]~*?" "<@" "@>;.,!:")) ; same as for latex-mode
)
)
Emacs : GNU Emacs 29.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.41, cairo version 1.18.0)
Package: 14.0.5