Is there any way to create a card that only displays a Youtube video in a dashboard? If not, then how would I show a card that simply contains the link to the video?
You can use hyperlinks in a Notebook card...you could also use the 'Doc Card' and have the youtube video embedded in PPT slide. https://www.youtube.com/watch?v=OEpbmaX2zJQ
I am unaware of a way to embed the video itself in a card or dashboard. But I would recommend exploring using a table card with HTML coding in it. Here is an example of how to create a link in a table card, I would assume that you could use a similar process to embed the video itself using HTML, although I am not an HTML expert.
create a beastmode for the table card:
CONCAT('<div><a href="WEB ADDRESS HERE" target="_blank">','WHAT YOU WANT THE LINK LABELED AS HERE','</a></div>')
The target="_blank" part means that clicking on the link will open a new tab