What is here missing is `org-capture-by-completing-read' so that
user may select among many various capture templates.
Compensating for initial bad design is expensive effort.
Are you suggesting something like this?:
#+begin_src emacs-lisp
(defun +org-capture-read (&optional arg)
"completing read interface for org-capture template selection.
ARG is passed to `org-capture'."
(let (parent)
(when-let* ((templates
(mapcar (lambda (template)
(let* ((keys (car template))
(parentkeys (car parent)))
(if (= (length template) 2)
(progn (setq parent template)
nil)
(cons (concat (when (and parentkeys
(string-prefix-p parentkeys keys))
(concat (cadr
parent) "/"))
(cadr template))
keys))))
org-capture-templates))
(selection (alist-get
(completing-read "capture template: "
(mapcar #'car (delq
nil templates))
nil 'require-match)
templates
nil nil
#'string=)))
(org-capture arg selection))))
#+end_src emacs-lisp
