Show Article Images means: "Don't remove images in introtext of article". Images that you have embedded directly in the text via editor.

For the second setting Show Intro/Full Image there was never an option to link the images but you can do that via a module override.

Therefore I think it's not an issue ("bug") but a feature request.

J3 doesn't implement new features. Perhaps for Joomla 4?

OK thanks very much, but before you get too smug about whether this a bug or feature, perhaps acknowledge that it seems rather random that this "feature" would appear only for Show Article Title and not Show Article Images. To a user new to Joomla, this would certainly seem more bug than feature.

I don't want to discuss anything. The decision was made: "No new features in Joomla 3".
That's what I've explained. Not more.

Show Article Images

Let's say you have 5 images embedded in your article introtext. You want to link them all? I don't think that a pr would be accepted, nor in J3 neither in J4.

before you get too smug

Stop to insult participants.

Could you be so kind and please provide the code that should be inserted to link the images via a module override ?
I would be glad to test if to link the images via a module override works.

Ask in a Joomla forum please but you should explain there about which images you are talking. For Article Images you need a regular expression, a preg_replace or similiar.

For Intro/Full Image
Change this line
https://github.com/joomla/joomla-cms/blob/3.9.18/modules/mod_articles_news/tmpl/_item.php#L27

to

		<a href="<?php echo $item->link; ?>">
			<img src="<?php echo $item->imageSrc; ?>" alt="<?php echo $item->imageAlt; ?>">
		</a>