I saw this with screenshots already for like 10-15 years now? It's some overly conservative policy to comply with fair use. I recall a page outlining that you should basically pick the minimum possible resolution that still allows you to distinguish the features of interest. I get why they do this, but it's really horrible from archiving and accessibility perspectives... And I would like to treat Wikipedia as one of the main archives of the world's collective knowledge.

All this goes to my "world has gone insane over IP law" bucket. Similar to people disallowing their games being streamed or even shared in screenshots.