IIRC It was added because too many people had been hacking together such a feature in their configurations, more often than not compromising their security. They added the option to reduce the amount of damage such a stupid much-asked-for feature deals.

P.S.: Honestly, I have used the feature before. While it’s usually funny, it can be brutal from time to time.

I was looking for a similar comment. Plasma does exactly that too. These are probably provided from this line in its .desktop file:

Keywords=Slideshow;Slides;OpenDocument Presentation;Microsoft PowerPoint;Microsoft Works;OpenOffice Impress;odp;ppt;pptx;

https://addons.mozilla.org/en-US/firefox/addon/youtube-recommended-videos/ Unhook "ignore"s them for me! It is available for other browsers too.

NixOS, mostly for the declarative configuration for almost everything. Atomic updates and independent installations of software for different projects are some other notable reasons.