Google slows down Firefox users when watching YouTube....

That is not their official website btw. The maintainer of uBO has stated that he doesn't want a website

He doesn't want a forum or a website, thus he won't have any costs and he won't have to accept donations meaning he doesn't have to deal with the administrative workload and that way he has more time to develop uBlock Origin.

Source: https://github.com/gorhill/uBlock/wiki/Why-don't-you-accept-donations%3F