I want an URL to appear in unmodified form even with inline oneboxing enabled

That is because inline oneboxing is enabled here in the site settings. Enter the URL with brackets if you insist that the URL must appear “raw”:

https://www.engadget.com/2019/01/25/youtube-conspiracy-video-recommendation-policy/

<https://www.engadget.com/2019/01/25/youtube-conspiracy-video-recommendation-policy/>

↑ notice the brackets.

I suggest going through Markdown Reference if you’d like more detail on formatting rules.