Sometimes. If it is really long then nah but if the youtuber mentions some links that I might be interested in like when they collab with another youtuber for example and I want to check out their channel but too lazy to type it. Or If I like a song and they have the name of the song in descriptions.
I like reading descriptions! It's interesting to see what they've said and sometimes I wanna know if I can find them elsewhere on the Internet, so I check them for links and stuff like that.
I encourage people to check the descriptions of my videos, purely because I include my information sources there as well as some further reading for anyone looking to expand their knowledge on the topic at hand.
It's good to check descriptions every once in a while anyway to get an idea of how other creators are structuring their own, whether or not yours needs improvement and also those sweet keywords, yo.