Although not nice for people that can't afford or don't want YouTube premium, this makes a lot of sense. Hosting videos costs a lot of money, and I doubt the YouTube Premium subscribers pay even nearly enough to pay for the hosting of all these videos. Personally I just have YouTube Premium as this also gives more money to the creators that make these videos.

I think an Open Source alternative would also have a lot of trouble with receiving enough funding to stay up. It would require a lot more donation compared to hosting mostly text based sites like Lemmy.