It's to do with who owns the rights to the videos.
Most of Tilvids' content is made by other people, and they only gave permission for the videos to be reposted on Tilvids.
You would have to talk to the videos' creators if you want these terms changed.
It's not something the server admin can change.
@FediVideos So, it's just a video hosting site that can also crosspost to Mastodon
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