PeerTube uses ActivityPub because this federation protocol is recommended by the W3C and is also used by other projects like the social network <a target="_blank" rel="noopener noreferrer" href="https://joinmastodon.org/">Mastodon</a>.
PeerTube is part of several actions assembled by Framasoft in the <a target="_blank" rel="noopener noreferrer" href="https://contributopia.org">Contributopia roadmap</a>.
PeerTube is a free software, not a secret formula that belongs to Google (in the case of Youtube) or to Vivendi/Bolloré (Dailymotion). This free/libre license guarantees our fundamental freedoms as users.