The threats to privacy with YouTube are different from PeerTube's. In YouTube's case, the platform gathers a huge amount of your personal information (not only your IP) to analyze them and track you. Moreover, YouTube is owned by Google/Alphabet, a company that tracks you across many websites (via AdSense or Google Analytics).
Web peers are not publicly accessible: because we use the websocket transport, the protocol is different from classic BitTorrent tracker. When you are in a web browser, you send a signal containing your IP address to the tracker that will randomly choose other peers to forward the information to. See <x id="START_LINK" ctype="x-a" equiv-text="<a href="https://github.com/yciabaud/webtorrent/blob/beps/bep_webrtc.rst">"/>this document<x id="CLOSE_LINK" ctype="x-a" equiv-text="</a> "/> for more information