I sometimes refer to "canonical questions" in my answers, and I've noticed that while I'm writing the answer, the preview of the text shows the actual title of the linked question rather than the URL, even though I've only pasted in a plain URL with no extra formatting, which is a nice feature.
However, once I submit the answer, those same links revert to being rendered as ordinary URLs again.
Example: I paste in the link https://unix.stackexchange.com/questions/218169/is-there-ever-a-good-reason-to-run-sudo-su
In the preview I can now see the above line rendered as
Example: I paste in the link Is there ever a good reason to run sudo su?
... but when I submit it, it will invariably revert to a plain URL1.
I obviously know about inserting links using the [link text](link URL) syntax, but since the preview is doing such a good job of showing the title of questions when linking to them with the URL only, I think it's a bit of a shame that this doesn't carry over from the preview to the submitted answer.
1 I'm almost 75% certain (i.e. "I seem to remember, but I may be wrong") that I've seen the formatting of links persist to the submitted answer occasionally, but never recently.