Speaking as a WikiPortraits organizer: Wikipedia primarily uses free media, and the for-profit event coverage is of course usually not releasing their photos under free licenses. Our photos are released under Creative Commons for use by Wikipedia and, well, anyone, and big events like the World Cup are where we can capture a lot of the most notable people at scale.

That being said, we're not just covering the big fancy events. We've done hundreds of events from indigenous festivals to minor league sports to science conferences. We've also donated equipment to wiki communities in Kenya, Ghana, and Benin to photograph their local events and culture, which are very undercovered on-wiki. The big events are what gets a lot of visibility and make the headlines but we do a lot more than that.

https://commons.wikimedia.org/wiki/Category:WikiPortraits_by...