YouTube has a moat a mile wide and ten thousand feet deep because their product is insanely expensive to provide. Think about it: they let you upload a basically-unlimited amount of video and then they store it for you forever, for free.
Every competitor which has tried to do this has been eaten alive by the costs of bandwidth and storage, even if they have a deep-pocketed corporate backer (e.g. Twitch will not let you store unlimited VODs like YouTube will). Some companies have managed to flank YouTube and carve out a little niche like short-form video, but I think building an actual YouTube competitor with the features people demand (again, unlimited uploads and eternal storage, for free) is more-or-less impossible.