(setq org-startup-folded t) makes Org files open with all headlines folded, my attention-deficient preference.

But then diffs are hidden when comparing Org files with ediff! Here is my ediff config:

(use-package ediff
:custom
(ediff-split-window-function 'split-window-horizontally)
(ediff-window-setup-function 'ediff-setup-windows-plain)
:hook
;;; Start Org files in maximally-unfolded view
(ediff-prepare-buffer . #'outline-show-all))

#emacs #OrgMode #ediff

@jameshowell if you re using org-elfeed , share the config of that too
Idk what I am doing wrong
When it worked it did like a charm

@jameshowell I had the almost-but-not-quite-the-same thing in my init file:

(use-package ediff
:defer t
:hook (ediff-prepare-buffer . org-fold-show-all)
:config
(setopt ediff-window-setup-function 'ediff-setup-windows-plain
ediff-split-window-function 'split-window-horizontally))

@Viiru In my business we call this "convergent evolution"