Wikipedia isn’t video hosting. The angles of nenual hosting cost for Wikipedia is around 3 million a year. YouTube probably costs nearly as much per hour to keep running.
500 hours of video are uploaded to YouTube every minute. That’s gonna be like 60 terrabytes every hour just in storage space increases.
If you were to try and host that on a cloud server like AWS the cost would increase millions of dollars every day. Google self-hosted, but it’s still unfathomingly expensive. There’s still questions over whether YouTube profitable even with all the ads and the subscriptions.