Every time you go to Wikipedia there's a huge banner asking for money implying it could shut down at any moment due to lack of funding.
In reality, the Wikipedia Foundation is doing just fine. In fact, they make so much money from donations, they spend (read: waste) massive amounts of it on various social ventures instead of using it on the service that caused people to donate in the first place.
Wikipedia runs one of the busiest websites in the world with a staff much smaller than any of those other sites. Like any company -- there's going to be priorities different than mine and waste.
But I'm ok being asked to chip in for what I get.
1. https://en.wikipedia.org/wiki/List_of_most_visited_websites